Tie-in is basically meaning to elaborate or give information to the prompt
I think there is a shift at “...assured him”. From reading the beginning, you would think the person is under arrest, “stay where you are”. But, the sentence goes on to say that the police officer ‘assured’ him that. He could’ve been in danger, so the officer was telling him that help was on the way, just stay put.
1. Dr. Martin Luther King Jr.: "I Have a Dream" Speech. ...
2. Charles Dickens: A Tale of Two Cities. .
Hopefully this is what you were looking for :).
It will either be B or C, goodluck!!