Which of the following sentences uses a metaphor? a. whenever she's hungry, my cat howls like a banshee. b. rafael looked as startled as a deer in headlights. c. my boss is a tornado. d. my old car gulps gasoline.

The answer is indeed letter C. My boss is a tornado.

Explanation:

A metaphor is a figure of speech that makes a comparison between two different things in order to attribute a quality of one of them to the other. To make such comparison, the metaphor states that "thing A is thing B". That's exactly what happens in letter C. My boss is a tornado. The literal meaning would be impossible, but we are able to understand that the boss has some characteristics in common with a tornado. Maybe he is relentless or destructive, just like a tornado.

Options A and B are similes. A simile is a figure of speech similar to a metaphor in the sense that it also makes a comparison. It needs support words that the metaphor doesn't use - "as" or "like". Option D is a personification because it attributes a living quality - gulping - to a non-living thing - a car.