Normally, about 10 percent of the hair on your head is resting (not growing). After a few months, the resting hair falls out and new hair begins to grow in its place. The growing time can last from 2 to 6 years. During the growing period, hair will gain about 1 centimeter a month. It is normal to experience hair loss every day. Some people experience too much hair loss from a variety of causes. Most people  _ believe that hair loss is caused by things like stress, scalp  ,or wearing hats. With the exception of stress, none of these factors has been proven to be a cause of hair loss. Stress is also not very likely unless you have experienced extreme physical or psychological suffering. This hair loss also doesn't last long. The real cause of hair loss lies with hormonal  problems. Hair loss occurs when male or female hormones are out of balance. An imbalance of hormones is usually genetic and cannot be cured. Male and female-pattern baldness is the most common form of hair loss. This is caused by a hormone called DHT, which helps in sexual development. An increase in DHT in a grown-up can lead to hair loss. There are also other causes of hair loss. Blood-thinners, some kind of medicines, and an excess of vitamin A, have all been shown to increase hair loss in certain people. Infections of the scalp can cause hair loss as well as certain diseases like diabetes. What is this passage mainly about?
The side effects of medicines. The effects of hormones. The causes of hair loss. Some ways to protect your hair.
Question: Normally, about 10 percent of the hair on your head is resting (not growing). After a few months, the resting hair falls out and new hair begins to grow in its place. The growing time can last from 2 to 6 years. During the growing period, hair will gain about 1 centimeter a month. It is normal to experience hair loss every day. Some people experience too much hair loss from a variety of causes. Most people  _ believe that hair loss is caused by things like stress, scalp  ,or wearing hats. With the exception of stress, none of these factors has been proven to be a cause of hair loss. Stress is also not very likely unless you have experienced extreme physical or psychological suffering. This hair loss also doesn't last long. The real cause of hair loss lies with hormonal  problems. Hair loss occurs when male or female hormones are out of balance. An imbalance of hormones is usually genetic and cannot be cured. Male and female-pattern baldness is the most common form of hair loss. This is caused by a hormone called DHT, which helps in sexual development. An increase in DHT in a grown-up can lead to hair loss. There are also other causes of hair loss. Blood-thinners, some kind of medicines, and an excess of vitamin A, have all been shown to increase hair loss in certain people. Infections of the scalp can cause hair loss as well as certain diseases like diabetes. What is this passage mainly about?
A. The side effects of medicines.
B. The effects of hormones.
C. The causes of hair loss.
D. Some ways to protect your hair.
Answer: