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.

Example Input: Calcium carbonate (CaCO_{3}) is considered a compound because it is made up of two or more  
 (A) molecules. (B) elements. (C) gases. (D) solids.
Example Output: B

Example Input: Which statement explains why a mother's unhealthy diet during pregnancy is harmful to her embryo's development?  
 (A) The embryo inherits half its chromosomes from its mother. (B) The embryo receives its food from its mother through the placenta. (C) The embryo receives oxygen through the placenta. (D) The embryo receives mutations carried by its mother.
Example Output: B

Example Input: Intense heat and pressure in Earth's crust can change sandstone into quartzite. During this metamorphosis, many properties of these rocks change. Which property of these rocks will most likely remain the same?  
 (A) mass (B) volume (C) crystal structure (D) particle shape
Example Output:
A