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.

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
D

Some pea plants always have peas with smooth skin. Other pea plants always have peas with wrinkled skin. How can a student best predict which kind of pea will grow from a seed that is planted?  
 (A) by checking the amount of water in the soil (B) by checking how often the pea plant receives sunlight (C) by checking how much space the plant will have to grow (D) by checking the type of peas growing on the parent plants
D

Which of the following is a first-level consumer?  
 (A) wolf (B) hawk (C) carrot (D) rabbit

D