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.

Which characteristic of frogs is an adaptation to living in water?  
 (A) strong legs (B) webbed feet (C) dull colors (D) moist skin
B

Which organisms contribute most to the decomposition of dead organisms?  
 (A) snakes (B) viruses (C) insects (D) bacteria
D

Which of these would best help a scientist discover a new planet?  
 (A) making a model of outer space (B) asking questions to other scientists (C) collecting information about planets (D) looking at the night sky with a telescope

D