Andy has been consuming a set number of calories and recently added an additional 100 calories in the form of a daily snack. although he is not trying to lose weight, he has lost one pound per week over the last two months. he wants to increase his level of activity and exercise, and he wants to return to his weight from two months ago. which strategy should he follow to prevent becoming underweight?

a. increase his activity and exercise levels and add more calories to gradually gain weight.

b. increase his activity and exercise levels and eat the same number of calories to gradually gain weigh.

c. increase his snacks to two or three per day until he reaches his target weight.

d. increase his calories consumed and do less activity and exercise until he reaches his target weight.