In the research lab, I have finally done it! I've discovered a new compound!

In the research lab, I have finally done it! I've discovered a new compound! I have determined that its empirical formula, but in order to determine its actual molecular formula, I need to know which of the following?

A. the number of moles of the compound in a 1.00 g sample of the substance

B. the density of the compound

C. the boiling point and freezing point of the compound

D. the molar mass of the compound.

E. none of these