Which of the Following Statements Concerning Temperature Change as a Substance

Which of the following statements concerning temperature change as a substance is heated is incorrect?

A) As a solid is heated, its temperature rises until its melting point is reached.
B) During the time a solid melts to a liquid the temperature remains constant.
C) As a liquid is heated, its temperature rises until its boiling point is reached.
D) During the time a liquid is changing to the gaseous state the temperature gradually increases while all the liquid is changed.