Final answer:
Solutions consisting of one metal dissolved in another are known as alloys, which are solid solutions.
Step-by-step explanation:
Solutions consisting of one metal dissolved in another are called alloys. This answer aligns with option C, a metal alloy, from the provided reference list. An alloy is a solid solution which consists of a metal (like iron) with some other metals or non-metals dissolved in it. For example, steel is an alloy of iron and carbon and it may contain small amounts of other metals. This is not to be confused with suspensions, which are heterogeneous mixtures where particles can settle, or with emulsions and colloids, which involve larger particles and different mixture properties.