All of the Following Uses of Commas Are Correct Except

Multiple Choice

All of the following uses of commas are correct except

A) Use commas to set off clauses that begin with the relative pronoun that.
B) Use commas to set off clauses that begin with the relative pronoun which.
C) Use commas to set off clauses or phrases that are unnecessary to the basic meaning of the sentence.
D) Use commas to set off appositives that rename a noun or pronoun.