Answer:
d.adjective.
Explanation:
A prepositional phrase that modies a noun is functioning as an adjective. For example: The woman in red is my sister. In red refers to a woman in particular ; the speaker wants to make it clear to which woman he is referring to. In this other example : The man by the window is my boss, the prepositional phrase by the window is telling , again, to which man the speaker is refering.
