Answer: D. Charlotte swept the floor after she finished cooking.
A subordinating conjunction can be a word or a phrase used to link the main clause to a subordinate clause. Some examples of subordinating conjunction include after, that, wherever, while, why, unless, in order to, even though, even if, etc. these words and phrases can be used to join the main clause to a subordinating clause. They always come at the beginning of the subordinating clause and they tend to talk about time, condition, comparison, cause, concession, and place. In the sentence “Charlotte swept the floor after she finished cooking”, the word “after” acts as subordinating conjunction and it helps in linking the main clause (Charlotte swept the floor) to the dependent clause (she finished cooking).