Final answer:
Option (c) contains a prepositional phrase at the beginning of the sentence, which modifies the main action of Veronica leaving a trail of breadcrumbs.
Step-by-step explanation:
The choice that has a prepositional phrase at the beginning is (c) To find her way back home, Veronica left a trail of breadcrumbs. A prepositional phrase usually starts with a preposition and includes the object that the preposition affects. In this sentence, "To find her way back home" is the prepositional phrase that provides information about why Veronica left the trail of breadcrumbs and is placed at the beginning to modify the main action.