With the kitten safely under the deck, the mother cat sauntered over to the dumpster.

The underlined phrase is which of the following? Underlined: under the deck.

Prepositional

Gerundial

Infinitive

Participal

The phrase under the deck is a prepositional phrase, because it begins with the preposition under.

Gerund and participle look the same - they are verbal forms that end in - ing.

Infinitive is to + verb (to be, to see ...)