Select the combination of letters that when sequentially placed in the gaps of the given letter series will complete the series. dc_b_a_ca_cad_a

acbbc acdbc ababc abbca

acdbc

If we break the series in this sequence then we find that: dc_ / b_a / _ca / _ca / d_a So, the correct sequence of the letters is dca / bca / dca / bca / dca and required code for the series is acdbc