Which best describes the role of resistance training in a healthy weight-gain program for an underweight person?

• A. Resistance training helps build lean muscle so weight gained includes a higher proportion of muscle rather than fat when combined with a caloric surplus.
• B. Only aerobic training should be used during weight gain because it exclusively promotes muscle hypertrophy when paired with extra calories.
• C. Resistance training is unnecessary because all weight gain will be lean if the person consumes enough calories regardless of physical activity.
• D. Resistance training always prevents any fat gain, so calorie distribution and food choices are irrelevant when exercising.

Answer: (A)