Answer: c) her fear that their promises will not last.
Step-by-step explanation: A simile is a figure of speech that consists in the comparison between elements that aren't obviously related, it uses the words "like" or "as" to make the comparison. In the given excerpt from Act II, scene ii of "Romeo and Juliet" by William Shakespeare, Juliet uses the simile: "Too like the lightning" to describe her fear that their promises will not last (because they were sudden and rash).