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.

[EX Q]: The parts of plants that make seeds are the  
 (A) roots. (B) stems. (C) flowers. (D) leaves.
[EX A]: C

[EX Q]: The main function of a fish's fins is to help the fish  
 (A) reproduce (B) see (C) breathe (D) move
[EX A]: D

[EX Q]: Which is most directly responsible for building up a river delta?  
 (A) erosion (B) leaching (C) subsidence (D) deposition
[EX A]:
D