Doesn’t is the correct answer!
I'd say the answer is - After I laundered my cell phone in my pants, I mad sure to track where it was, especially when close to water.
It specifically states that the pants were laundered with the cell phone in them, and that he doesn't want to make that same mistake again.
My is the personal pronoun here. Because when you say "my room", it means you possess that room and the personal thing here is your room.
A) he is willing to live by his new convictions
