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.

When do mutations help make an ecosystem more sustainable?  
 (A) when mutations decrease the number of individuals in an ecosystem (B) when mutations increase the number of individuals in an ecosystem (C) when mutations decrease the number of species in an ecosystem (D) when mutations increase the number of species in an ecosystem
D

Which unit is used to express the amount of energy in food?  
 (A) Calorie (B) degree Celsius (C) milliliter (D) gram
A

A student conducts an experiment to determine the effect soap has on the growth of radish seeds. He puts 30 seeds in three different dishes: one with water, one with a 1% soap solution, and one with a 10% soap solution. Which type of data should he collect?  
 (A) size of seeds and amount of solution used (B) time of day and number of seeds germinated (C) type of detergent and amount of solution used (D) number of seeds germinated and average length of shoot

B