TASK DEFINITION: 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.
PROBLEM: Question: When it is very warm what happens to the speed of items? 
 Option1: speed up 
 Option2: slow down 
 Explanation: For a given medium, sound waves travel more slowly at lower temperatures.

SOLUTION: speed up

PROBLEM: Question: When a baby drinks very little milk from their mother then their mother makes 
 Option1: less milk 
 Option2: more milk 
 Explanation: The more the baby suckles, the more prolactin is released, which causes more milk to be produced.

SOLUTION: less milk

PROBLEM: Question: What happens to John's risk of contracting a disease as he gets older? 
 Option1: it decreases 
 Option2: it increase 
 Explanation: The older a person is, the greater their chance of developing a cardiovascular disease.

SOLUTION:
it increase