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.

Often organisms seem similar in their outward appearances. For example, a porpoise and a shark seem closely related, but they are not. Such similarity is the result of  
 (A) convergent evolution. (B) adaptive radiation. (C) artificial selection. (D) genetic equilibrium.
A

Which of these statements about nonrenewable resources is true?  
 (A) They are inexpensive. (B) They help keep the air clean. (C) They can take millions of years to form. (D) They are used because they are easily removed from the ground.
C

Tay-Sachs disease is a recessive genetic disorder. If only one gene is present, an individual is a carrier. What is the probability of two healthy Tay-Sachs carriers having a child that has the disease?  
 (A) 0% (B) 25% (C) 50% (D) 75%

B