Out of these options, the right answer is
D. It's most important to determine whether or not a source is reliable before using it
The other three choices here are very false, in fact.
A memoir is a collection of the true stories that happened in someone's or in a subject's life. For example, a biography is a memoir. The primary purpose of a memoir is to document highlights of one's life, make it naturally relatable, so that other people who may read it will be inspired.
Translators have to travel a lot for their jobs.
Social media messes up some peoples brains by other people filling it up with hate, lies, and rudeness. Like on Facebook, there are very rude/mean people that tell others that they are unloved, ugly, worthless, and so much more. So therefore it messes with peoples brains by filling them up with lies.