Answer:  Below, the bold words indicate prepositional phrases. Only these sentences contain prepositional phrases  

The man in the house seemed to be asleep.

The soldiers crept cautiously through the tunnel.  

I was informed that the bus would arrive in 45 minutes.

Prepositions are connecting words that act like bridge

A prepositional phrase is a group of words that beings with a preposition and ends with the object of the preposition.

For example, we went fishing with Ben.    Now in this example the connecting word (the bridge) is WITH.

Taking the above example:

We went fishing with Ben  

Now, here “with” is the preposition and Ben is the object of the preposition.