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.

[Q]: Which statement best describes the development of a human embryo?  
 (A) A single cell becomes many cells. (B) Each cell has a different function. (C) Many cells combine to form one cell. (D) All the cells have the same function.
[A]: A


[Q]: Because copper is a metal, it is  
 (A) liquid at room temperature (B) nonreactive with other substances (C) a poor conductor of electricity (D) a good conductor of heat
[A]: D


[Q]: Which scientist formulated rules that describe the observable relationships of plant traits to the traits of the ancestor plants?  
 (A) Linus Pauling (B) Gregor Mendel (C) James Watson (D) Albert Einstein
[A]:
B