单选题

　　[阅读选择]Do you think sitting and studying all the time will improve your grades？ Think again. Getting some exercise may help， too.

　　New research with older people suggests that taking regular walks helps them pay attention better than if they didn‘t exercise.

　　Walking regularly helps elderly people______.

　　A、lose weight

　　B、become happier

　　C、concentrate better

　　D、look younger