In the sequence A E C B % 7 D $ E B 5 C ? 3 D E 9 @ 2 #, all the vowels are dropped from the arrangement. After removing all vowels, which symbol or character will be the twelfth from the left end of the remaining sequence?

Introduction / Context:
This question involves a mixed sequence of letters, digits and symbols. You are asked to remove all vowels from the arrangement and then determine which character is in a specific position in the modified sequence. This tests both your ability to identify vowels and to track positions carefully after elements are removed, which is a common task type in reasoning and alphabet test sections.

Given Data / Assumptions:

The original sequence is: A, E, C, B, %, 7, D, $, E, B, 5, C, ?, 3, D, E, 9, @, 2, #.
Vowels to be removed are A and E only, because these are the only vowels appearing in the sequence.
After removing all vowels, we consider the new sequence from the left end.
We must find the twelfth character from the left in this vowel free sequence.

Concept / Approach:
The strategy is to process the sequence in order, discard every vowel we encounter, and record the remaining characters. Once we have the new list without vowels, we count from the left to find the twelfth element. It is important not to misclassify consonants or symbols as vowels and to be systematic in counting so that positional errors do not occur.

Step-by-Step Solution:

Verification / Alternative check:
As a quick verification, you can recount the positions in the final sequence, or even copy the new sequence separately and underline every fifth element to keep track, then move to the twelfth. Another check is to ensure that all instances of A and E were removed correctly and that the number of remaining characters is 16, matching the count we obtained. When all steps are rechecked, the twelfth character consistently comes out as D, which confirms the answer.

Why Other Options Are Wrong:

3 appears at position 11, not at position 12, so although it is close, it is not the required twelfth element.

@ appears later at position 14, so choosing it would reflect an incorrect count of positions in the modified sequence.

9 is the thirteenth character and not the twelfth, so it does not satisfy the positional requirement of the question.

Common Pitfalls:
Candidates may forget to treat each occurrence of a vowel separately and accidentally leave one E or A in the sequence. Another common error is to miscount positions after removal, especially when the sequence is long and contains many symbols. Writing down the new sequence clearly and numbering each position helps prevent these mistakes and ensures the final positional count is accurate.

Final Answer:
After dropping all vowels from the given arrangement, the twelfth character from the left is D.