"I am not afraid of my enemies, but by God, you must look out when you get among your friends." meaning

can you say more details

it is the background information on the characters and setting explained at the beginning of the story. the exposition will often have information about events that happened before the story began. the exposition is often the very first part of the plot.

answer is b,

"the tracer looks harmless in flight, but the pilot’s bitten lips and white knuckles suggest how dangerous it can be."

it was correct.