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.

[EX Q]: You need to move products across the ocean from Boston to Europe. What are your choices?  
 (A) ship or airplane (B) truck or ship (C) truck or airplane (D) tunnel or ship
[EX A]: A

[EX Q]: In the 17th century, Galileo proposed a hypothesis to explain how suction pumps work. Galileo's hypothesis was disproved, but later it helped Torricelli in the development of an instrument for measuring atmospheric pressure. How did Galileo's hypothesis most likely help with the development of this new technology?  
 (A) by leading Galileo to design a different technology (B) by allowing another scientist to critique Galileo's hypothesis (C) by providing evidence of the effects of atmospheric pressure (D) by inspiring another scientist to test an alternative hypothesis
[EX A]: D

[EX Q]: Which shows one example of a physical change and one example of a chemical change?  
 (A) boiling water and melting wax (B) rusting iron and baking a cake (C) dissolving powder and shredding paper (D) freezing water and burning coal
[EX A]:
D