You are given a question or fill-in-the-blank question, two answer options (Option1 and Option2) and an Explanation. Your task is to find the correct answer (return the string of the correct option, not option1/2) for the given question from the given options and using explanation.

[Q]: Question: The air gets thicker when it is 
 Option1: hot 
 Option2: cold 
 Explanation: Increasing air temperature decreases atmospheric pressure.
[A]: cold


[Q]: Question: If Jim starts exercising and performs no anaerobic exercises, would his muscles get 
 Option1: bigger 
 Option2: smaller 
 Explanation: Anaerobic exercises cause muscles to get bigger and stronger.
[A]: smaller


[Q]: Question: If Jim adds more carbon dioxide to the ocean, the level of acidity in the ocean becomes 
 Option1: greater 
 Option2: smaller 
 Explanation: With higher levels of dissolved carbon dioxide in ocean water, the water becomes more acidic.
[A]:
greater