Definition: You are given a question on a random topic. 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 of the following most likely indicates the presence of water in the hydraulic system in a piece of farm machinery?
(A)A grayish, milky fluid (B)Excessive fluid use (C)Excessive thinning of the fluid (D)A noisy relief valve

A