Question

Type the prepositional phrase in this sentence. the settlers rationed their supplies of dried meat, vegetables, and flour.

Answer 1

A prepositional phrase, as the name itself suggests, has to do with prepositions. So it is a phrase which starts with a preposition, and includes one, or more words after it. 
In this case, the prepositional phrase is of dried meat, vegetables, and flour. The phrase acts as an adjective - what kind of supplies? (Those) of dried meat...

Answer 2

The prepositional phrase is "their supplies of". From the sentence we know what was being rationed, the supplies. The phrase "their supplies of" is a preposition that enables to sentence to contain the items contained therein - dried meat, vegetables, and flour.