To identify the pattern in the given sequence, let's break it down step by step:

The sequence given is: ABC_ _ ABC_DABBCD_ABCD

Firstly, we observe that the known parts of the sequence (excluding the blanks) are repeated segments: "ABC", "ABC", "DABC", and "DABC". From this, we can see that "ABC" is a recurring theme and "DABC" seems to follow after "ABC".

Let's analyze the segments around the blanks:

The first blank segment: ABC_ _
The second blank segment: BCD_

Given that the first three letters are in the pattern "ABC", it is reasonable to presume that another letter will either complete or continue the pattern. If we follow the letters as "D", the sequence would continue as "ABCD", matching the observed segments "DABC".

To ensure consistency and correct repetition, consider the sequence structure before and after the known segments, thus we have:

The first blank segment should be completed by the letter "D".
The second blank segment should be completed by "AB", continuing the sequence.

Conclusively, the pattern after analyzing and ensuring consistency is:

ABCDA BCD

Thus, the complete sequence following the pattern would be: ABCDABCD, forming the option:

Option B - CDAB

Therefore, the answer which completes the sequence is:

Option B - CDAB

Arrangement and Pattern · Logical Reasoning and General Mental Ability · UPSC Civil Service

MCQ (Single Correct Answer)