Answer: D. Mustard seeds
About 80% of the developed world's food is derived from the rainforests. Avocardo, coffee, cocoa, orange, grapefruits, lemons, tomatoes, maize and sweetcorn. The rainforest humid environment is suitable for the growth of these plants. But the mustard plant requires the hot climatic conditions. It requires the direct sunlight which may not be provided by the rainforest because of the long trees with wide canopy.