Given three choices for packing travel snacks for a week-long trip, analyze caloric efficiency per volume and choose the best set: (A) 500 g fresh fruit, (B) 200 g mixed nuts and dried fruit, (C) 300 g rice cakes and raw vegetables. Which option maximizes total caloric intake per suitcase volume while remaining nutrient-dense?

• A. Option A: 500 g fresh fruit, because fresh produce always yields more calories per gram than dried or fatty foods when packed tightly.
• B. None: Carry only electrolyte drinks since liquids always provide the highest calorie-per-volume ratio regardless of composition.
• C. Option C: 300 g rice cakes and raw vegetables, because starchy items plus water-heavy vegetables are typically the most calorie-dense and shelf-stable option.
• D. Option B: 200 g mixed nuts and dried fruit, because dried fruit and nuts have high calorie density and provide fats, carbs, and micronutrients in a small volume ideal for travel.

Answer: (D)