Which statement is a description of Boyle’s law?

The temperature and volume of a gas are directly proportional when pressure is constant.
The temperature and volume of a gas are inversely proportional when pressure is constant.
The volume and pressure of a gas are directly proportional when temperature is constant.
The volume and pressure of a gas are inversely proportional when temperature is constant.

The volume and pressure of a gas are inversely proportional when temperature is constant.