8. in the second sentence, the phrase "inside his trouser pockets" is a/an
a. prepositional phrase.b. independent clause.c. subordinate clause.d. subject of the sentence.

Its A)
It cannot be a independent clause because that phrase itself cannot be its own sentence. For example in the sentence "I need some water to drink.", "I need some water" is an independent clause, because it can be a sentence that makes sense not like "to drink", because that makes no sense. So as I said before I got to talking about clauses

3 is the right answer to the question.