You are given a science question (easy-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

Input: Consider Input: Often organisms seem similar in their outward appearances. For example, a porpoise and a shark seem closely related, but they are not. Such similarity is the result of  
 (A) convergent evolution. (B) adaptive radiation. (C) artificial selection. (D) genetic equilibrium.

Output: A


Input: Consider Input: When a person speaks, the type of wave produced can be described as all these except  
 (A) transverse. (B) mechanical. (C) compression. (D) longitudinal.

Output: A


Input: Consider Input: Which of these is unique to the process of scientific investigation?  
 (A) observing an event as it occurs (B) discussing results with other experts (C) publishing the results on a webpage (D) collecting data in an experiment


Output: D