After my brother died in an accident, my mother was in deep sadness. I was only a four-year-old girl at the time, but I still understood the sudden shift in my mom's attitude towards safety. Suddenly everything around us was potentially dangerous. Overnight, the world had gone from a playground to a dangerous zone. I grew up with a lot of limits and rules. I couldn't walk home from school by myself, even though everyone I knew already did. I couldn't go to summer camp because what if something happened to me? As I got older, the list of things of fear got longer. My whole life was divided into "things you should avoid", and "things you needed to do in order to have a good, long life." I became a natural worrier. I worry about things like getting cancer, losing my wallet, car accidents, earthquakes, and losing my job -- disasters big and small, real and imagined. The funny part is that you'd never know it by looking at my life. In fact, I've developed a rule for myself: If it scares me, then I have to do it at least once. I've done lots of things that my mom would have worried about: I've ridden a motorcycle; I've traveled --a lot. I've performed stand-up comedy, and I'm planning my second wedding. There's something else I don't usually talk about, but it's a cornerstone in my belief: When I was 14, my mother died suddenly in a car accident. At my mom's funeral I remember making a choice. I could either live out the rest of my life trying to be "safe" or I could be brave enough to live out a fulfilling, exciting and, yes, sometimes dangerous life. I worry that I may have betrayed  my mother by writing her in this light, but she has been a driving force in my life and, in the end I think she would have been proud of me. Courage isn't a natural character of human beings. I believe that using courage is like developing a muscle. The more often I do things that scare me or that make me uncomfortable, the more I realize that I can do a lot more than I originally thought I could do. Even though I inherited   my mother's cautious nature. I've also come to believe that fear can be a good thing, if we face it. Believing that has made my world a less scary place. In the writer's childhood, the limits and rules were used to   _  .
improve her behavior develop her independence be in memory of her dead brother protect her from possible danger
Question: After my brother died in an accident, my mother was in deep sadness. I was only a four-year-old girl at the time, but I still understood the sudden shift in my mom's attitude towards safety. Suddenly everything around us was potentially dangerous. Overnight, the world had gone from a playground to a dangerous zone. I grew up with a lot of limits and rules. I couldn't walk home from school by myself, even though everyone I knew already did. I couldn't go to summer camp because what if something happened to me? As I got older, the list of things of fear got longer. My whole life was divided into "things you should avoid", and "things you needed to do in order to have a good, long life." I became a natural worrier. I worry about things like getting cancer, losing my wallet, car accidents, earthquakes, and losing my job -- disasters big and small, real and imagined. The funny part is that you'd never know it by looking at my life. In fact, I've developed a rule for myself: If it scares me, then I have to do it at least once. I've done lots of things that my mom would have worried about: I've ridden a motorcycle; I've traveled --a lot. I've performed stand-up comedy, and I'm planning my second wedding. There's something else I don't usually talk about, but it's a cornerstone in my belief: When I was 14, my mother died suddenly in a car accident. At my mom's funeral I remember making a choice. I could either live out the rest of my life trying to be "safe" or I could be brave enough to live out a fulfilling, exciting and, yes, sometimes dangerous life. I worry that I may have betrayed  my mother by writing her in this light, but she has been a driving force in my life and, in the end I think she would have been proud of me. Courage isn't a natural character of human beings. I believe that using courage is like developing a muscle. The more often I do things that scare me or that make me uncomfortable, the more I realize that I can do a lot more than I originally thought I could do. Even though I inherited   my mother's cautious nature. I've also come to believe that fear can be a good thing, if we face it. Believing that has made my world a less scary place. In the writer's childhood, the limits and rules were used to   _  .
A. improve her behavior
B. develop her independence
C. be in memory of her dead brother
D. protect her from possible danger
Answer: