instruction:
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.
question:
Question: Ivan yells across a canyon in the morning when it is cold and again later in the afternoon when it is hot. During which time did his voice travel the slowest? 
 Option1: morning 
 Option2: afternoon 
 Explanation: For a given medium such as air, sound has a slower speed at lower temperatures.
answer:
morning


question:
Question: Dan needs to stay warm in the woods, and can bring one animal for body heat to sleep next to him. Given the choice between a horse and cat, Dan will choose the 
 Option1: cat 
 Option2: horse 
 Explanation: Therefore, an object with more mass has greater thermal energy than an object with less mass, even if their individual atoms are moving at the same speed.
answer:
horse


question:
Question: If demand for solar power were to fall, the power would become _____ expensive. 
 Option1: less 
 Option2: more 
 Explanation: Solar power is expensive, but as demand increases technology improves and costs decrease.
answer:

more