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]: A delta at the mouth of a river is the direct result of  
 (A) runoff from sewage. (B) deposition of sediment. (C) an ancient glacier that passed through. (D) an underground river flowing to the ocean.
[A]: B


[Q]: A student measured liquid with a graduated cylinder. Which of the following units could be used to record the volume of the liquid?  
 (A) pounds (B) meters (C) grams (D) milliliters
[A]: D


[Q]: Dr. Mendez specializes in patients who have osteoarthritis. His patients often complain of pain and swelling due to loss of cartilage. Which system is most affected by this disease?  
 (A) cardiovascular (B) digestive (C) immune (D) musculoskeletal
[A]:
D