The correct option is C Fruits
The most important foods for human survival includes vegetables, cereals, fruits, pulses and oil seeds. Most of these are fruits. For example, caryopsis is popularly called as grain and is the fruit typical of the family Poaceae (or Gramineae), which includes wheat, rice, and corn. Considering that the fruit wall and the seed are intimately fused into a single unit, and the caryopsis or grain is a dry fruit, little concern is given to technically separating the terms "fruit" and "seed" in these plant structures. So, most important foods are derived from fruits and not from stem, leaves and roots. Thus, option B is correct.