Which of these happens last? Nina hits a drum.
Nina hears the sound of her drum.
Sound waves travel through the air.
The surface of the drum vibrates, creating sound waves.

which is the following what are you asking?

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.