In alphabet series, some alphabets are missing which are given in that order as one of the alternatives below it. Choose the correct alternative.
mnonopqopqrs _ _ _ _ _
_ bbca _ bcca _ ac _ a _ cb
_ abb _ _ bb _ a _ bbab _ ba
abca _ bcaab _ ca _ bbc _ a
_ _ babbba _ a _ _
_ baa _ aab _ a _ a