Which is the better strategy in multiple choice exams

My toughest teacher taught us this:
Read EVERY answer first.
When an answer is obviously WRONG, put a small "x" next to it.
Read the remaining answers again.
If one uses words you have NEVER heard of, put the "x" next to it.
If one sounds like it is or could be the correct one, put a small "y" next to it. Then as you read the remining choices, you know this one is prolly the right answer.
What you are doing is eliminating the choices, one by one, so you can easily see which ones to ignore.

Maybe littering, cutting down trees and pollution