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]: Researchers are developing new types of crop plants with desirable characteristics such as disease resistance and drought tolerance. Crossing plants so that the next generation will express desirable traits is best described as  
 (A) selective breeding. (B) natural selection. (C) genetic engineering. (D) gene sequencing.
[A]: A


[Q]: In which state are molecules of a substance arranged in the most orderly way?  
 (A) gas (B) liquid (C) plasma (D) solid
[A]: D


[Q]: One of the functions of a topographic map is to  
 (A) gauge local rainfall amounts. (B) study the area's geological history. (C) predict the severity of earthquakes. (D) show the surface features of an area.
[A]:
D