Apostrophe and Simile i think.
Answer: b because it is correct
He probably pointed out that they looked similar because Stryver asked one of the two accusers after being given the note, if he had ever seen someone that looked like Darnay before.
We can infer that it had something to do with their appearance.
And you could have mentioned that this is from "A Tale Of Two Cities"
Explanation:

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