In an either or argument, you have 2 options. You can choose either this or that. It is like taking sides.
The first one, "was revealed" makes it passive,
The answer is
- <span>The soldiers crept cautiously through the tunnel.</span><span>.
- </span><span>I was informed that the bus would arrive in 45 minutes.
Prepositional phrases begin with a preposition and will be followed by noun, pronoun, gerund, or clause which displayed by two sentences above
(Through) + ( the tunnel)
(in) + ( 45 minutes) </span>
