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

A

M, T, R, K, T, R

B

K, M, R, T, T, T

C

K, T, R, M, T, R

D

M, R, T, K, T, T