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]: The cheetah population around the world has decreased because of poaching and loss of habitat. The surviving population is found to have similar alleles. Which factor is endangering the species' survival the most?
(A) harmful genetic mutations (B) shrinking of the gene pool (C) decrease in competition (D) increase in adaptations
[A]: B

[Q]: Andre learned that plants survive through a process called photosynthesis. Which substance do plants produce during photosynthesis?
(A) minerals (B) nitrogen (C) soil (D) sugar
[A]: D

[Q]: What would happen if a magnet was placed in the center of a plastic bowl containing a mixture of iron filings and sand?
(A) The sand will be repelled by the magnet. (B) The iron filings will be attracted to the magnet. (C) The sand will be attracted to the magnet. (D) The iron filings will be repelled by the magnet.
[A]:
B