1. 

In the following question, a letter series is given. Some of the letters of the series are missing. This missing letters are given in same order as one of the four/five alternatives below the series. Find out the correct alternative.

a__ba__c__aad__aa__ea
A. babbb
B. babbd
C. babbc
D. bacde

Answer: Option D

Explanation:

Pattern of the series as shown below

abba/acca/adda/aeea => bacde

Hence, the missing letters are bacde.