Six years ago, I walked into a local animal shelter on a cold, rainy day. Although my house was already full of cats and dogs, I still couldn't resist an occasional visit to the shelter. This time as I was walking down the row of pens full of barking dogs I noticed a small boy looking into one of them.  He had a malnourished  looking body and a bony face with a big nose sticking out of the middle of it. He was looking at a small, golden dog. Its bony ribs were showing and its thin tail was folded between its legs. It wasn't begging for attention like the other puppies but was hiding in the corner instead. The boy looked up at me with sad eyes and asked what was wrong with it. "It was probably abused and abandoned", I said. "That is why it is so scared." The boy immediately turned to an older lady and said, "Grandma, I want this one." The old woman smiled and walked to the front desk to fill out the adoption forms. I followed and asked about the boy. I found out that he'd had a rough start in life too. She had just gotten custody  of him after the state had taken him from his parents. She had hoped getting a dog would make it easier on him. I looked back at him, holding his scared puppy, and said a prayer for them both. It was yesterday. I was driving down the road enjoying a gloriously sunny, spring day. Then in a green front yard I saw the boy. His teenage body was tall and strong. His nose no longer seemed big but fit well into his smiling face. He was throwing a ball to a healthy, happy dog with shining golden hair. His little act of love and kindness had indeed gone a long way. It had saved a dog's life, healed his own heart, and given this middle-aged man fresh hope for us all. The reason why the dog was so scared is that   _   .
it was afraid of the cold it had been ill-treated it was frightened by the boy it was frightened by the author
Question: Six years ago, I walked into a local animal shelter on a cold, rainy day. Although my house was already full of cats and dogs, I still couldn't resist an occasional visit to the shelter. This time as I was walking down the row of pens full of barking dogs I noticed a small boy looking into one of them.  He had a malnourished  looking body and a bony face with a big nose sticking out of the middle of it. He was looking at a small, golden dog. Its bony ribs were showing and its thin tail was folded between its legs. It wasn't begging for attention like the other puppies but was hiding in the corner instead. The boy looked up at me with sad eyes and asked what was wrong with it. "It was probably abused and abandoned", I said. "That is why it is so scared." The boy immediately turned to an older lady and said, "Grandma, I want this one." The old woman smiled and walked to the front desk to fill out the adoption forms. I followed and asked about the boy. I found out that he'd had a rough start in life too. She had just gotten custody  of him after the state had taken him from his parents. She had hoped getting a dog would make it easier on him. I looked back at him, holding his scared puppy, and said a prayer for them both. It was yesterday. I was driving down the road enjoying a gloriously sunny, spring day. Then in a green front yard I saw the boy. His teenage body was tall and strong. His nose no longer seemed big but fit well into his smiling face. He was throwing a ball to a healthy, happy dog with shining golden hair. His little act of love and kindness had indeed gone a long way. It had saved a dog's life, healed his own heart, and given this middle-aged man fresh hope for us all. The reason why the dog was so scared is that   _   .
A. it was afraid of the cold
B. it had been ill-treated
C. it was frightened by the boy
D. it was frightened by the author
Answer: