Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions.

Television and Kids

Television is very popular and even has some benefits for kids. It helps very young children learn the letters of the alphabet, and helps other kids learn about science, cultures, and world events.

However, researchers show that too much TV is bad for children. For one thing, there is a link between watching more than four hours of TV a day and being overweight. For another thing, many TV shows are violent and upsetting. Watching these shows may cause kids to be more fearful. And of course, more time in front of the TV means less time to study. Too much TV may also be the cause of lower grades. Experts do not agree on the solution to these problems. Some say that kids should watch only educational programs; others say kids should watch no TV at all. And others suggest teaching them to watch TV as occasional entertainment, not as an everyday hobby.

What is the passage mainly about?