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.

Organisms contribute to the water cycle mainly through the process of  
 (A) irrigation. (B) evaporation. (C) precipitation. (D) transpiration.
D

If an environment becomes warmer and drier, the change that would most likely help a species adapt would be an increase in its  
 (A) amount of body fat. (B) amount of body hair. (C) ability to climb trees. (D) ability to store water.
D

Camels have humps on their backs that store fat, allowing them to survive for many days without food. This makes camels well suited to desert life. This characteristic is an example of  
 (A) adaptation. (B) instinct. (C) migration. (D) hibernation.

A