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:
A scientist is searching for areas where new solar systems might form. What feature is the scientist looking for?  
 (A) a star similar to our Sun (B) a cloud of dust and gas (C) an oxygen-rich atmosphere (D) a gravitational acceleration of 9.8 m/sec2

Ex Output:
B


Ex Input:
Bridge inspectors have determined that a bridge is unsafe. Which of the following is the BEST design process the company should use to correct the problem?  
 (A) identify the problem-repair the bridge-plan for the repair (B) plan for the repair-repair the bridge-identify the problem (C) plan for the repair-identify the problem-repair the bridge (D) identify the problem-plan for the repair-repair the bridge

Ex Output:
D


Ex Input:
Coal is used for generating about 53% of the electrical energy in the United States. Which of these environmental issues is directly contributed to by the burning of coal?  
 (A) beach erosion (B) ozone depletion (C) overfishing (D) air pollution

Ex Output:

D