Definition: You are given a question on astronomy. Astronomy is a natural science that studies celestial objects and phenomena. You are also given 4 answer options (associated with "A", "B", "C", "D"), out of which only one is correct. You need to answer the question by selecting the correct option. You should only answer with the choice letter, not the whole answer.
Input: Which is not an essential requirement for life as we know it?
(A)The ability to breathe oxygen (B)The ability to make energy from sunlight or to eat things that do (C)A source of organic molecules (D)A and B

D