According to this excerpt, the two brothers represent C. good and evil.
As you can see in this passage, the right-handed twin represents good - he lives in heaven, and watches over men, providing them with the help they need. On the other hand, we have the left-handed twin, who represents evil - he lives among men, and rejoices when he sees warfare and suffering.
C I think cause in the book it say revenge but guilt kinda has almost the same
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"
Answer:
It reminds them about the lost souls
