The best adverb clause which would complete the sentence is given above. This is because, the sentence is talking about Mexico as a country in which Oscar was born in. The country has a fascinating history going by its rich culture and traditions of the people living in it.
An independent clause is a phrase that can stand on its own as a sentence. "I don't like snakes" has a subject, verb, and noun; therefore it is a complete sentence. None of the other answer choices are complete sentences; they are dependent clauses.
