Explain why a large animal, such as a human, needs special adaptations to organs that exchange materials with the environment (such as the lungs, small intestine and kidney), but a single-celled organism does not.

i think that d. wind is the answer.   i missed the question when i answered a. currents.

the answer to your question is:

c. complementary base-pairing

the correct option is option d

because they are eaten by the frog and the frog getseaten by the snake and the snake by the eagle