What does the author suggest with the line sometimes wondering, almost with envy?

appropriate

adjective: correct or right for a particular situation or occasion

verb 1: to take and use for a purpose

verb 2: appropriate also means to steal

inappropriate

unsuitable, esp. for the particular time, place, or situation:

bevy means a large group or thing of a certain kind.

the development of trade during the middle age increased to the change given in the agriculture, which gave money, industry and markets a bigger importance in economy. the agriculture production was more than the consumption, which meant the creation of wider markets out of the areas. besides, with the end of multiple wars, the population increased and new trade routes were created.

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.