Answer:
D) object of a preposition
Explanation:
"Maria" is functioning as the object of the preposition “to" in this sentence.
In this sentence a noun functions as the object of a preposition by coming after a preposition.
By definition of what an object of a preposition is, it is any noun that comes right after a preposition.
I think it was well written because the concept seems interesting in itself that people could go back in time or into the future. Albert Einstein has a better theory though