Nutritional Needs Vary by Age and Activity Steps: - Identify that diets must match individual requirements based on age, sex, and activity. - Evaluate option A: A diet for an elderly man lacks calories and nutrients for a growing, active boy, causing malnutrition. - Check B: Malnutrition can indeed occur at any life stage due to imbalances. - Assess C and D: Protein needs peak in growth phases but decline later; energy needs are highest in children relative to size but total intake is lower than in active adults. Why A is correct: - Nutritional guidelines (e.g., RDA) specify higher energy and nutrient demands for adolescents versus seniors, so a senior's diet provides insufficient intake for a boy's growth and activity, leading to malnutrition. Why the others are wrong: - B: Correct, as malnutrition arises from any dietary imbalance at any age, not just specific periods. - C: Protein requirements decrease after growth phases, like in adulthood and old age. - D: Young children need energy per kg body weight but lower total intake than active adults due to smaller …