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.

Ex Input:
Which of the following was most likely the cause of the extinction of 60-100 species of native birds in Hawaii since the arrival of colonists?  
 (A) habitat destruction (B) volcanic eruptions (C) increased salinity (D) tidal waves

Ex Output:
A


Ex Input:
One method of heat distribution is a baseboard forced hot water system. A baseboard system carries hot water through a pipe that passes through many small, flat plates called fins. What is the purpose of these fins?  
 (A) to dissipate the heat of the hot water flowing through the pipe (B) to prevent the baseboard from coming in contact with hot surfaces (C) to replace the heated air leaving the system with cold air (D) to prevent dust and other particles from entering the baseboard

Ex Output:
A


Ex Input:
Which is the correct sequence for the stages in the life cycle of a butterfly?  
 (A) larva; pupa; egg; adult (B) egg; pupa; larva; adult (C) adult; larva; pupa; egg (D) egg; larva; pupa; adult

Ex Output:

D