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: Mike wants his voice to travel slowly, so he will speak in a room that is 
 Option1: colder 
 Option2: warmer 
 Explanation: For a given medium such as air, sound has a slower speed at lower temperatures.

A: colder
****
Q: Question: Evan is a farmer and needs to plant on a slope. For a faster flow of water, he should choose a slope that is 
 Option1: steeper 
 Option2: gentler 
 Explanation: A gentle slope favours slower flow of surface water, reduces erosion, and increases availability of water to plants.

A: steeper
****
Q: Question: Dana washes her hands a lot, so her bacteria has muted to help to resist antibiotics. As that bacteria increases in numbers, the mutation becomes 
 Option1: common 
 Option2: rare 
 Explanation: Bacteria with a mutation the helps resist antibiotics increase in numbers, so the mutation becomes more common.

A:
common
****