Q: Fact 1: Some birds are pollinators that co-evolved with plants. Fact 2: If the plant is green, it is a producer. Given the two facts above, some birds are pollinators that co-evolved with what other type of organism?

Available options:
(A). animals.
(B). humans.
(C). vegetation.
(D). producers.
(E). parasites.
(F). warm-blooded.
(G). Conifers.
(H). mammals.
A:
(D).