How could you use melting and boiling point to identify a substance

At low temperatures than melting point the substance remain as a solid. Then from melting point temperature to boiling point the substance will remain as a liquid. This is the temperature at which a liquid become a gas. When we increase the temperature of a liquid it will become gas at its boiling point.

Explanation:

alfred von schlieffen, german army chief of staff, was given instructions to devise a strategy that would be able to counter a joint attack. in december, 1905, he began circulating what later became known as the schlieffen plan. schlieffen argued that if war took place it was vital that france was speedily defeated.

the right answer is c i just did the question.