Q: In this task, you're given an article, a question which often contains a blank and four options (associated with "A", "B", "C", "D"). Your task is to find the correct answer (from the given options) for the question from the given article and return one of the options from "A", "B", "C", and "D". Do not generate anything else apart from one of the following characters: "A", "B", "C", "D". There is only one correct answer for each question.
Article: Some people think that they will get ill if they use their brains too much.  It is not true.  Through many researches, scientists show us that the more you use your brains, the better they will be, and the wiser you will become. Of course, if you want to keep your mind clear and be energetic , you must take a proper rest and study properly.  To the teenagers, using their brains in the morning is good for their health. There are many ways to rest.  One is a peaceful rest.  Sleep is a peaceful rest.  Another is an active rest.  For example, take a walk outdoors, do morning exercises every day.  To change the way of the brains'activities is also a good way to rest. In everyday life, to eat some eggs, meat, fresh vegetable and fruit is also good for the brains. Wish you a wise man and a happy life. 
 Question: If   _   ,your mind will be clean? 
 Options: (A) You go swimming in a lake (B) You are active in learning (C) You have a good rest and study properly. (D) You can sing a song
A:
C