How does the phrase "a million mosquitoes" affect the passage?
A. It implies that there is a large amount of mosquitoes in the yard.
“A million something” (in this case mosquitoes) is an hyperbolic figure of speech used to imply a large or excessive amount of something. Option B about Jack not being a reliable narrator could have been a possible answer but the passage is written using a third-person point of view, so Jack is not a narrator.