The correct combination of characteristic equation Qn+1 of S-R flipflop and J-K flipflop respectively is

• A. QnR + S̅ and JQn + K̅Qn
• B. Q̅nR + S and J̅Qn + K̅Qn
• C. QnR̅ + S and JQn + K̅Q̅n
• D. QnR̅ + S and JQ̅n + K̅Qn