In the given letter series, some letters are missing. The missing letters are given in order in one of the alternatives below. Choose the correct alternative.
_acca_ccaa_caacc_acc

Explanation

The missing letters, in order, are c – a – a – a, so the required choice is "caaa". This is one of those letter-series questions where inserting the candidate into all four gaps is faster and safer than trying to "eyeball" the pattern. The archived solution to this paper likewise gives option B.