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.

Input: Consider Input: Cell membranes allow some molecules to move freely across the membrane, while other molecules are restricted. Which term best describes this capability of a cell membrane?  
 (A) semipermeable (B) impervious (C) resilient (D) unyielding

Output: A


Input: Consider Input: Bones support the body. What pulls and pushes on bones to move them?  
 (A) blood (B) nerves (C) muscles (D) skin

Output: C


Input: Consider Input: The hereditary material in corn plants can be altered by scientists so the plants produce more corn. Which term identifies this process?  
 (A) environmental degradation (B) ecological succession (C) natural selection (D) genetic engineering


Output: D