A hot air balloon has an air vent that keeps the air pressure inside and outside the same. Allen observes that a hot air balloon rises up when the gas molecules inside it are heated. Which of the following laws is used to understand the behavior of the gas and why?

The high temperature brings the gas molecules closer together according to Charles's law because this law describes how a gas will behave at constant pressure.
The high temperature makes the gas molecules spread apart according to Charles's law because this law describes how a gas will behave at constant pressure.
The high temperature lowers volume according to Boyle's law because this law describes how a gas will behave when the number of moles remains constant.
The high temperature raises volume according to Boyle's law because this law describes how a gas will behave when the number of moles remains constant.