Answer:
d. Temperature and number of molecules of gas
Step-by-step explanation:
Boyle's Law states, "The volume of a fixed mass of a gas is inversely proportional to the pressure if the temperature remains constant."
Let's examine the words.
"… volume…is inversely proportional to the pressure …" This means that volume and pressure are the variables.
"… fixed mass of a gas …" means that the number of molecules is constant.
"… temperature remains constant" speaks for itself.
a, c, and e are wrong, because pressure is a variable.
b is wrong, because volume is a variable.
