In alphabet series, some alphabets are missing which are given in that order as one of the alternatives below it. Choose the correct alternative. - ab _ bcbca _ _ c _ bab

Answer: D. ccaa

The series is abcbc / bcaca / cabab.
Thus, the series consists of three sequences.
The first sequence begins with a, the second with b and the third with c.
Each sequence consists of a letter followed by other two letters repeated twice.