instruction:
You are given a science question (hard-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:
Which phase of the Moon occurs after a waxing gibbous?  
 (A) waning gibbous (B) waxing crescent (C) full moon (D) new moon
answer:
C


question:
Petrified palm trees are found in sedimentary rock near glaciers. The presence of the petrified palm trees most likely provides evidence for which statement?  
 (A) There was once more water in the area. (B) The area was once grassland. (C) The climate in the area was once tropical. (D) There are active faults in the area.
answer:
C


question:
Sheep Challenge Evolution A species of sheep lives on the Scottish island of Hirta. Hirta has plenty of grass for the sheep to eat, and no natural predators of the sheep live on the island. Some sheep have dark wool, and some have light wool. The sheep with dark wool tend to be much larger and stronger than the sheep with light wool. However, researchers have found that in the last 20 years, the sheep with light wool have increased in number. Usually, strength and size help animals survive and breed. On Hirta, sheep with light wool outnumber sheep with dark wool because sheep with light wool  
 (A) produce more wool (B) have a more restricted diet (C) produce fewer offspring each year (D) have a better chance of surviving and reproducing
answer:

D