I believe A is the correct answer
An appositive is a noun or noun phrase that renames another noun right beside it, it can be short or long combination of words here's an example: The insect, a cockroach, is crawling across the kitchen table. i hope this helps you :)
I am not really sure I need the answer asap too
The prepositional phrase is "along the beach"
along = preposition
the beach = object of the preposition
