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:
In the morning, students observed puddles of water all over the playground. What would best explain why the playground was dry in the afternoon?  
 (A) Animals drank the water. (B) The wind stopped blowing. (C) Someone dried the puddles. (D) The water evaporated during the day.

Ex Output:
D


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:
A student uses a fan and a box of sand to model the formation of sand dunes. This model shows the effect of which natural factor on the landscape?  
 (A) wind (B) water (C) temperature (D) gravity

Ex Output:

A