PLZ HELP

Two chemists measure the densities of an unknown metal sample. They both find that the sample has a density of 8.94 g/mL. Chemist A uses a chart
and says that the metal must be copper since the density of copper is exactly 8.94 g/mL. Chemist B says that the metal could be a mixture of two or
three different kinds of metals with an average density of 8.94 g/mL.
Which of the scientists' conclusions could be valid?

A.) Scientist B's conclusion is valid because most metals are alloys.

B.) Both scientists' conclusions could be valid.

C.) Scientist A's conclusion is valid because it is supported by evidence.

D.) Neither scientist's conclusion is valid because it is impossible to identify unknown substances.