Sterling silver is:

A) a heterogeneous mixture

B) colloid

C) an element

D) Homogeneous mixture

It's D

Explanation:

It's an alloy so it is not pure. If you take a small sample and analyze it, the mixture will be similar throughout. Think of Gatorade as a homogeneous mixture because it is the same concentration of all ingredients throughout. Think of pizza for heterogeneous mixtures. There isn't the pepperoni (or whatever you prefer) throughout.