1.  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 _ aa _ caab _ c _ abb _ c

A. bbcaa
B. bcbca
C. cabac
D. cbbac

Answer: Option D

Explanation:

The series is abc / aabc / aabbc / aabbcc.

First all the letters occur once, then a occurs twice, then both a and b occur twice and finally all the three letters appear twice.