I need help with this please

What is the meaning of the word checking as it is used in this sentence from the second paragraph of the passage?

Geoffrey is writing a paper investigating friendly-fire incidents in recent us military actions. which paragraph topic would be relevant to his paper and would therefore merit inclusion in his final draft? a) a paragraph criticizing us military actions in the viet nam war b) a paragraph discussing how friendly-fire incidents are investigated c) a paragraph describing what basic boot camp is like for a new army enlistee eliminate d) a paragraph discussing how hard an extended military service can be on a family

Why does the author of exploring the titanic give background information about his youth and education? to show his lifelong love for the ocean