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]: Two identical books are on opposite ends of a table. Which of these would increase the gravitational force exerted between the two books?  
 (A) decrease the distance between the books (B) decrease the mass of the books (C) decrease the mass of the table (D) decrease the temperature in the room
[A]: A


[Q]: Where do good bacteria grow to help keep people healthy?  
 (A) in the brain (B) in the blood (C) on the skin (D) on the bones
[A]: C


[Q]: After fields of crops are harvested, parts of the plants remain on the ground. For many years, farmers have mixed these plant remains into the soil. Which most likely results from this practice?  
 (A) More minerals are lost from the field. (B) More nutrients in the soil are dissolved. (C) The organic matter in the soil increases. (D) The number of organisms in the soil decreases.
[A]:
C