If Charles' law is to be applied to a given sample of a gas, then it must have constant pressure.
What is gas law?
Gas law are the hypothesis which tells about the behavior of gas at different conditions.
According to the Charles' Law, volume of the gas at any constant pressure and no. of moles of gas is directly proportional to the temperature of the gas at that condition. Charles' law is represented as:
V ∝ T, where
V = volume of gas
T = temperature of gas
Hence option (a) is correct i.e. pressure.
To know more about Charles' Law, visit the below link:
https://brainly.com/question/26725812
