Answer: In this sentence we have subject, verb, subject compliment and prep phrase.
Explanation: I have found that your question is about English grammar.
''I need to identify the subject, verb, and any complements (direct object, indirect object, subject complement, objective complement) and the prepositional phrases of the following sentences.''
Boundary is - subject
is - verb
edge - subject compliment
of the Atlantic ocean - prepositional phrase
