instruction:
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.
question:
A leaf is covered in mud during a landslide. After one million years, this leaf will most likely be ___.
(A) a fossil (B) an animal species (C) a new plant species (D) a nonrenewable fuel
answer:
A

question:
The number of fish in a lake suddenly increases. How will the increase most likely affect the lake?
(A) There will be less water in the lake. (B) More plants will grow in the lake. (C) More frogs will live in the lake. (D) There will be fewer insects in the lake.
answer:
D

question:
Coral reefs are found in shallow tropical ocean waters. A coral reef is a diverse ecosystem that is supported by the photosynthesis of marine plants and the algae that live within the tissues of the coral. Given this information, when would the waters in a coral reef likely have the highest dissolved oxygen concentration?
(A) 7 a.m. (B) 2 p.m. (C) 9 p.m. (D) midnight
answer:
B