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: As Earth's climate becomes cooler it will develop _____ varieties of vegetation? 
 Option1: less 
 Option2: more 
 Explanation: The warmer a climate is, the more types of vegetation it will have and the greater the rate of biological weathering.

A: less
****
Q: Question: If Mona is adding chemicals to her swimming pool and she lowers the pH value of the water, what happens to the acidity of the water in the pool? 
 Option1: increase 
 Option2: decrease 
 Explanation: The lower the pH value is, the greater is the concentration of hydrogen ions and the stronger the acid.

A: decrease
****
Q: Question: Mona is creating some vases out of clay. If she decreases the mass of her vases by using less clay on them, what happens to the amount of matter they contain? 
 Option1: decrease 
 Option2: increase 
 Explanation: The greater the mass of an object, the more matter it contains.

A:
decrease
****