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.
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Question: The vampire finches in the Galápagos Islands peck at another species of bird, the blue-footed booby, until the finches make a wound. Then, the finches drink the booby's blood. Scientists think that many generations ago finches used to peck bugs off the booby, and the behavior evolved to what it is today. Which statement best describes the birds' relationship generations ago and the relationship today?  
 (A) The old relationship was parasitic. The new relationship is mutualistic. (B) The old relationship was mutualistic. The new relationship is parasitic. (C) Both relationships are parasitic. (D) Both relationships are mutualistic.

Answer: B


Question: A student plants rosebushes in her front yard. The student is frequently seen pulling weeds from the base of the rosebushes. What is the most likely reason that the weeds are pulled?  
 (A) Weeds add fertilizer to the soil. (B) Weeds use nutrients the roses need to grow. (C) Weeds increase the bacteria in the soil. (D) Weeds consume most of the oxygen.

Answer: B


Question: Which land form is the result of the constructive force of a glacier?  
 (A) valleys carved by a moving glacier (B) piles of rocks deposited by a melting glacier (C) grooves created in a granite surface by a glacier (D) bedrock hills roughened by the passing of a glacier

Answer:
B