Answer:
"through New Mexico."
Explanation:
Prepositional phrases are groups of words that contain a preposition, its object, and the word it modifies. This means that it will be a phrase used before a noun or pronoun and acting as a preposition.
In the given sentence "the Rio Grande flows through New Mexico", the prepositional phrase is "through New Mexico". This is because the phrase starts with the preposition "through" and contains an object.
