Answer:
B. A barely mobile hard roll
Explanation:
A metaphor is a figure of speech that directly refers to one thing by mentioning another one. A metaphor is usually employed in order to provide clarity or to create a link between two ideas. In this case, a turtle is being compared to a "barely mobile hard roll." The comparison relies on the shape of a turtle's shell (roll), its resistance (hard) and the slow way a turtle moves (barely mobile).
