Pedro Would Like to Gain Weight,but Despite Eating Regular Meals

Pedro would like to gain weight,but despite eating regular meals and having no disordered eating practice or eating disorder,his BMI dropped from 19.0 to 16.2 in one year.According to this information,his physician will need to ________.

A) let him know that it is not necessary for him to gain weight,because his BMI is in the healthy range
B) treat him with hypermetabolic medications
C) determine whether he has a serious chronic disease,such as inflammatory bowel disease
D) provide him with a low-fat,low-carb diet that provides 900 kcal/day to gain weight