Select the option that represents the letters that, when sequentially placed from left to right in the blanks below, will complete the letter series.

_ M _ _ G _ D _ _ M _ C G _ D C

G D C M C G D M

After dividing it into groups  and comparing the corresponding term we, get "G D C M C G D M" as the repetitive term because it follows the pattern.

G M DC G M D CG M D C G M D C