Answer:
The answer to your question would be that the sentence that contains an appositive phrase is the following one: In Montreal, my favorite city, many people speak French. The appositive phrase is the NP "my favorite city".
Step-by-step explanation:
An appositive is a noun or noun phrase that renames another noun right beside it. In this case, "my favorite city" renames the noun "Montreal". Nonessential appositives are always separated from the rest of the sentence with commas. This is so because the information they provide is not necessary to complete the meaning of the sentence. If they were removed, the meaning of the sentence would not be altered (see a).
a) In Montreal, many people speak French