. . . . . . we do exercise, we will remain healthy. A. More B. If C. Unless D. When

The correct answer is: If we do exercise, we will remain healthy.

The other options are incorrect because:

• More does not make sense in this context.
• Unless means “if not”, which is not the meaning of the sentence.
• When means “at the time that”, which is not the meaning of the sentence.

The sentence is about the cause and effect of exercise and health. The word “if” is used to introduce a condition that is necessary for something to happen. In this case, the condition is that we do exercise. The effect of doing exercise is that we will remain healthy.