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:
What are produced in both the male and female reproductive systems in humans?  
 (A) sperm (B) nutrients (C) fertilized eggs (D) sex cells

Ex Output:
D


Ex Input:
Which of the following compounds is most likely to be part of living organisms?  
 (A) C?H??O? (B) BF? (C) MoCl? (D) CsI

Ex Output:
A


Ex Input:
Angela wants to report daily weather conditions. In which unit should Angela record the air temperature?  
 (A) degrees Celsius (B) centimeters (C) milliliters (D) grams

Ex Output:

A