Witch literary device helps add depth to characters by showing previous events

Allusion. This is when you bring in characters or events from another story to amplify or add context to your own work. An allusion can be risky because your reader may not have read what you're referring to.

Explanation:

the gas pressure p, gas volume v, and gas temperature t are given in the formula:   pv=nrt,

r is the gas constant, and n is the number of gas moles.

if the container is cooled and remains under atmospheric pressure, where r is a constant that does not change, the volume of the container remains the same, the conclusion is drawn that, with all other values ​​unchanged, the number of gas moles n, is decreases.

the right answer is a.