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