Critical Reasoning

Although most people know that the exercise is good for the body, few realize the extent to which it is valuable to the mind. The blood circulates more rapidly after the physical exertion, thus allowing all of the body's organs to operate more efficiently. This increased activity enables brain to receive more oxygen, thereby creating a higher capacity for concentration.

The main point in the argument above is that

1. the greater the amount of oxygen brain receives, the better it functions.

2. Exercise is a mental as well as physical activity.

3. Exercise helps the brain more than it does the rest of the body.

4. people can greatly improve their powers of concentration by exercising more often.

5.exercise serves more than one purpose.

OA is 5