Select the correctly punctuated sentence.
AJohn are you certain you understand? Emily asked.
B"John, are you certain you understand?" Emily asked.
C"John, are you certain you understand," Emily asked?
D"John are you certain you understand?" Emily asked.
E"John are you certain, you understand," Emily asked?
AJohn are you certain you understand? Emily asked.
B"John, are you certain you understand?" Emily asked.
C"John, are you certain you understand," Emily asked?
D"John are you certain you understand?" Emily asked.
E"John are you certain, you understand," Emily asked?