Choose the answer which best rewords the italicized portion. If you think the original wording is best, choose option A.
Etiquette, which is sometimes unwritten, is a code that governs the expectations of social behavior of people.
Explanation
Answer: A - The best choice is “Etiquette, which is sometimes unwritten, is”
The clause “which is sometimes unwritten” includes relevant information, but is not needed to complete the sentence. Therefore, it is a non-restrictive clause and should be offset by commas at the beginning and at the end of the phrase. “Which” is a pronoun used with non-restrictive clauses. Generally, “that” is a part of a restrictive clause.
