Is a comma requires before the word "and" when listing?

What sentence correctly uses it’s underlined relative pronoun?

Johnny just received a failing grade on his science exam. lucy oversaw johnny’s paper, and she asked him about it. johnny snapped at her shouting, “it’s none of your business! ” which of the following is the psychological response johnny exhibited towards lucy? select one: a. dismay b. irritability c. hesitation d. hopelessness

Where sarah live? a. are b. is c. do d. does