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 _ _ _ b_ bbaa _

A. abaab
B. abbab
C. baaab
D. babba

Answer: Option C

Explanation:

The series is abb / aab / abb / aab.

Thus, the pattern abb, aab is repeated.