Select the combination of letters that when sequentially placed in the blanks of the given series will complete the series. JL_N_J_PND_NP_DJ_P_D

M, D, P, N, J, N, O P, M, D, N, J, O, N P, D, M, J, N, O, N M, D, N, P, N, J, O

P, D, M, J, N, O, N

J L P N D / J M P N D / J N P N D / J O P N D P , D , M , J , N , O , N