B It keeps your insides from falling out.

问题：

B

It keeps your insides from falling out. It helps you warm up when you are cold, and it can cool you off when you are hot. It lets you feel things by touch.
What is this Your skin, of course! What does your skin ask for in return for all the wonderful things it does Just a little care! So let’s learn how to take good care of our skin.
Like the heart and stomach, your skin is an organ(器官). In fact, it is the largest organ in your body. Unless there’s a problem, you may not think about your skin very much. But skin has an important job to do.
Your skin is protecting you. Your skin keeps you from getting sick. When you take care of your skin, you are helping your skin do its job. Taking care of your skin today will help you have no problems in the future.
Clean skin is happy skin! One simple way to take care of your skin is to keep it clean. Keeping your hands clean is very important. When washing your hands, use warm water. Wet your hands, and then use soap. You should wash your hands carefully everywhere.
You’ll also want to use warm water, but not too hot, when you take a bath. Use soap to clean your body. Don’t forget under your arms and behind your ears! Your face needs attention, too. It’s a good idea to wash your face once or twice a day with warm water.

What does this passage mainly talk about ( )

A．Taking care of your skin.

B．Your skin.

C．An important organ.

D．Keeping yourself from getting ill.