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:
What is the function of the nucleus in a cell?  
 (A) provides energy (B) provides nutrients (C) controls activity (D) controls movement
answer:
C


question:
Marta studied different forms of energy. Which two types of energy travel in waves?  
 (A) light and sound (B) electrical and sound (C) chemical and light (D) chemical and electrical
answer:
A


question:
Which statement best describes the size of the Sun?  
 (A) The Sun is medium-sized compared to other stars. (B) The Sun is the largest and brightest star in the universe. (C) Most of the stars in the universe would fit inside the Sun. (D) Most of the stars in the universe are smaller than the Sun.
answer:

A