Correct Answer: temperature remains constant

Solution : The correct option is temperature remains constant.

Even when heat is repeatedly applied to a liquid at its boiling point, its temperature stays constant. Instead of raising the temperature of the liquid, the extra heat is used to convert it to vapour during boiling. The energy is used to dissolve the intermolecular interactions that hold liquid molecules together, enabling them to escape into the gas phase. As a result, the liquid's temperature remains constant until the entire liquid has vaporized.