Answer:
The answer is indeed metaphor.
Explanation:
The excerpt provided in the picture belongs to the famous novel "Don Quixote". In the passage, we find a figure of speech called metaphor. A metaphor is employed by the writer when he wishes to make an indirect comparison between two different things. The objective is to attribute the quality of one to the other. A simile is also a figure of speech that establishes a comparison but, unlike the metaphor, it uses support words such as "like" or "as". A metaphor simply states that one thing is the other thing.
In the excerpt, the mule is compared to a castle when the narrator says, "drove his heels into his castle of a mule." The intention is to have readers understand that the mule has one or more qualities that would normally be associated with a castle. It's probably big, strong, and resilient. Therefore, the best option for this question is letter A) metaphor.
