Select the Letter of the Sentence with the Correct Relative

Multiple Choice

Select the letter of the sentence with the correct relative pronoun and the correct punctuation.
-_____

A) Senator Hererra , which is campaigning for reelection, stopped in my city.
B) Senator Hererra, who is campaigning for reelection, stopped in my city.
C) Senator Hererras who is campaigning for reelection stopped in my city.