TASK DEFINITION: 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.
PROBLEM: A girl found the skull of an animal. She did not know what the animal was but she was sure that it preyed on other animals for its food. What clue led to this conclusion?  
 (A) The eye sockets faced sideways. (B) The skull was much longer than it was wide. (C) There was a projecting ridge along the top of the skull. (D) Four of the teeth were long and pointed. (E) The jaws could move sideways as well as up and down.

SOLUTION: D

PROBLEM: Scientists have studied the specific stages in the life cycle of stars. In which stage do stars spend most of their lifetime?  
 (A) red giant (B) black dwarf (C) white dwarf (D) main sequence

SOLUTION: D

PROBLEM: A force of 5 N is required to increase the speed of a box from a rate of 1.0 m/s to 3.0 m/s within 5 s along a level surface. What change would most likely require additional force to produce the same results?  
 (A) reduce the mass of the box (B) increase the mass of the box (C) make the surfaces of the box smooth (D) make the surface of the floor smooth

SOLUTION:
B