Answer:
Your answer is most probably A). B) implies that nuts are the only thing for birds to eat in a rainforest, which doesn't make sense, C) implies that the insects would need a widely-varied diet to survive, but again there's an abundance of things that a hungry bug can eat, so they don't need a wide dietary coverage, D) suggests that there may be droughts in the area for which the plant may need to be prepared, but in the RAINforest droughts are uncommon.
