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 Cindy swam closer to the ocean surface, it got lighter and _____. 
 Option1: warmer 
 Option2: cooler 
 Explanation: Water density increases as salinity and pressure increase, or as temperature decreases.

A: warmer
****
Q: Question: Sandra sees a tiny glacier, and notes that it has smaller tributary glaciers flowing into it, in valleys that are 
 Option1: shallow 
 Option2: deep 
 Explanation: Smaller tributary glaciers, like tributary streams, flow into the main glacier in their own shallower U-shaped valleys.

A: deep
****
Q: Question: Carey watched the exhaust smoke leave the pipes, and saw it disintegrate into the garage. The smoke had _____ density now. 
 Option1: higher 
 Option2: lower 
 Explanation: If we take a certain amount of gas from one container and place it into another, larger container, the gas expandsto fill the larger container. The same mass of gas is now in a larger volume, the gas now has a lower density.

A:
lower
****