The prepositional phrase is "On the bike trail", the preposition is "On", and the object of a preposition is "bike trail"
Explanation:
A prepositional phrase is a group of words that is formed with a preposition, an object and a word or words that modify that object. A preposition is a word that connects nouns pronouns or phrases, and an object of a preposition is noun, noun phrase, or pronoun that follow a preposition, in the sentence "Our walk on the bike trail was refreshing." have a prepositional phrase "on the bike trail", a preposition "On" and an object of preposition "bike trail"
