Aprepositional phrase contains what?

a. a pronoun followed by a preposition
b. a prepsosition followed only by a noun or pronoun
c. a preposition followed by a noun, pronoun, or phrase

The answer is:  [C]: a preposition followed by a noun, pronoun, or phrase.

Note: Answer choice "A" is incorrect.  
A 'prepositional phrase'  ALWAYS begins with a preposition.

Answer choice "B" is incorrect.  A 'prepositional phrase' does, in fact, always, start with a preposition, but does not HAVE to be followed by ONLY a [noun or pronoun].