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.

[EX Q]: Which is a major difference between the life cycles of different types of plants?  
 (A) the way they die (B) the energy they use (C) the way they reproduce (D) the way they make food
[EX A]: C

[EX Q]: A student walking quickly while carrying an orange on his lunch tray stops suddenly. The orange will most likely roll off the tray due to  
 (A) inertia of the orange. (B) centripetal force of the orange. (C) the friction acting on the orange. (D) the balanced forces acting on the orange.
[EX A]: A

[EX Q]: What is the most likely function of a turtle's hard shell?  
 (A) convert energy (B) increase speed (C) provide protection (D) allow for reproduction
[EX A]:
C