If the Liquid of a Pure Substance Has a Lower

Multiple Choice

If the liquid of a pure substance has a lower density than the solid,what is the effect on the pressure-temperature phase diagram?

A) The vapor-pressure curve arches upward.
B) The normal melting point is above room temperature.
C) The melting-point curve has a negative slope.
D) The vapor-pressure curve arches downward.
E) The melting-point curve has a positive slope.