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 light-year is a measure of
(A) time. (B) energy. (C) distance. (D) direction.
answer:
C

question:
When nitrogen-rich runoff from farms enters a nearby farm, it causes abundant growth of algal mat on the pond surface. As a result, underwater plants in the pond begin to die. Identify the limiting factor that is most responsible for causing the underwater plants to die.
(A) oxygen (B) sunlight (C) nitrogen (D) carbon dioxide
answer:
B

question:
Vascular plants have tissue called xylem. Which of these is transported by the xylem?
(A) food made by the plant (B) water needed by the plant (C) pollen for plant reproduction (D) carbon dioxide for photosynthesis
answer:
B