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 would be a safe practice to exercise during laboratory investigations?  
 (A) using open flames to heat all materials (B) keeping your cell phone on the laboratory countertop (C) knowing where your instructor/laboratory leader is at all times (D) removing your safety glasses when moving from station to station

Ex Output:
C


Ex Input:
Which characteristic of sound makes it possible for bats to fly in the dark without hitting any objects?  
 (A) refraction (B) reflection (C) conduction (D) amplification

Ex Output:
B


Ex Input:
What statement describes what happens to the carbon dioxide waste produced by a developing baby during pregnancy?  
 (A) It is carried by the umbilical cord to the placenta and then to the mother's blood. (B) It is released from the fetus by its breathing and then is absorbed by the placenta. (C) It is released through the fetal urine and then exits through the umbilical cord. (D) It is carried through shared blood vessels and then to the mother's lungs.

Ex Output:

A