Answer: C. metaphor.
Explanation: a metaphor is an indirect comparison between two thing that aren't obviously related to each other. A simile is also a comparison but it uses words like "like" to make it, for example: you are strong like a rock. The given sentence is a clear example of a metaphor, where the speaker is comparing a person to the smell of summers, we can see that it doesn't use "like" or any other word to make the comparison.
