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.

Plants growing in a pond release a gas that fish need to survive. Which gas do the plants release that fish use?
(A) helium (B) hydrogen (C) nitrogen (D) oxygen
D

Which is the greatest benefit of sexual reproduction?
(A) capable of reproducing by meiosis (B) ability to reproduce without a mate (C) ability to produce genetically different offspring (D) capable of producing offspring genetically identical to parent
C

The rate of acceleration of an object is determined by the mass of the object and
(A) the initial velocity of the object. (B) the forces acting on the object. (C) the direction of movement of the object. (D) the change in kinetic energy of the object.
B