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:
Cell membranes allow some molecules to move freely across the membrane, while other molecules are restricted. Which term best describes this capability of a cell membrane?  
 (A) semipermeable (B) impervious (C) resilient (D) unyielding

Ex Output:
A


Ex Input:
After playing outside on a cold day, Jaime went inside to wash his hands. Although the water was normal temperature, he noticed that it felt warmer than usual. What would explain this phenomenon?  
 (A) His body had more kinetic energy than the water. (B) Heat flowed from a cooler substance to a warmer substance. (C) The water from the faucet had a higher temperature than his skin. (D) The thermal energy in the room was higher than the thermal energy outside.

Ex Output:
C


Ex Input:
The sum of protons and neutrons in the nucleus of an atom is called the  
 (A) valence. (B) mass number. (C) chemical property. (D) electrical charge.

Ex Output:

B