the use of an insect is particularly significant because of all the things in this world, the insect is often seen as bothersome, disgusting, and easily squashed. While some people may see value in insects (for pollination, for example), most find them easy to ignore or horrific.
The answer is B because convalesce means "to recover health and strength after illness" This is the only reasonable answer.
The final draft. It's the stage where you want to fix minor details before turning it in, correcting the small stuff like grammar and spelling and punctuation.