Options:
(A). human cells;
(B). fertile;
(C). engines;
(D). gametes;
(E). Energy;
(F). food;
(G). white;
(H). backbones;
Given those answer options, answer the question: Fact 1: Adult sponges produce eggs and sperm. Fact 2: BTW, a gamete is like an egg or sperm. Given the two facts above, what do adult sponges produce?
A:
(D).