Which of the following statements is punctuated correctly? a. The new student in my class who moved here from North Carolina is very nice.
b. The new student in my class, who moved here from North Carolina, is very nice.
a
b

b. The new student in my class, who moved here from North Carolina, is very nice.

Explanation:

You use commas "," either to separate independent clauses- parts of a sentence that can be their own sentence- or to separate a dependent clause at the beginning of a sentence- a part of a sentence that can't be its own sentence.

In this case, the the beginning of the sentence, "The new student in my class," which cannot stand on its own as a sentence, must have a comma after it because that is one of the comma rules. It's a dependent clause because it does not have a complete thought. It doesn't say what "the new student in my class" is doing or what is happening to them.

So, the answer is B!