Answer the following question given this paragraph: 

The elements mercury, gold, and copper display properties that are common of metals. Mercury ( left ) is the only metal that is a liquid at room temperature. Even in its liquid form, it still has a high luster. Gold ( middle ) is malleable and can be formed into very thin sheets called gold leaf. Because copper ( right ) is ductile, inexpensive, and a good conductor, it is used extensively in electrical wiring.


Q: What is the only metal that is a liquid at room temperature?

 Choices:

- copper

- aluminum

- tin

- mercury

A:
mercury
