In the three term alphabet series BDE, HJK, NPQ, ?, which of the given options should replace the question mark so that the pattern of letters is maintained throughout the sequence?

Introduction / Context:
This problem involves a sequence of three letter groups: BDE, HJK, NPQ, and a missing term. The goal is to identify the correct group of letters that continues the pattern. Such alphabet series questions are standard in aptitude tests and assess the ability to observe and extend sequences based on consistent steps in the alphabet positions of letters.

Given Data / Assumptions:

• Known terms: BDE, HJK, NPQ.
• Each term has three capital letters.
• We expect a consistent rule to apply to the first, second, and third letters across terms.
• No wrap around is needed here because letter positions stay within A to Z.
• Options: UWX, TVW, VXY, WYZ.

Concept / Approach:
The method is to represent each letter by its alphabetical index and look at how these indices change from one term to the next. If there is a constant difference for each position across terms, we can easily predict the next term by applying the same difference. This numeric view simplifies pattern detection and reduces the risk of visual confusion.

Step-by-Step Solution:
Step 1: Convert BDE to numeric positions: B(2), D(4), E(5).Step 2: Convert HJK: H(8), J(10), K(11). The changes from BDE to HJK are +6, +6, and +6 respectively.Step 3: Convert NPQ: N(14), P(16), Q(17). The changes from HJK to NPQ are again +6, +6, and +6.Step 4: The pattern is therefore a constant increment of +6 for the first, second, and third letters.Step 5: Apply this to NPQ. Starting from N(14), add 6 to get 20, which is T. From P(16), adding 6 gives 22, which is V. From Q(17), adding 6 gives 23, which is W.Step 6: The next term must therefore be TVW.

Verification / Alternative check:
We can quickly verify by mentally reconstructing the sequence: BDE (2, 4, 5), HJK (8, 10, 11), NPQ (14, 16, 17), and then TVW (20, 22, 23). Each transition adds 6 across all positions. None of the other options matches this exact pattern when checked; they would require different or inconsistent increments.

Why Other Options Are Wrong:
UWX would represent 21, 23, 24, which are not all 6 positions after N, P, and Q. VXY and WYZ similarly do not result from a uniform +6 step from NPQ. Therefore, they break the discovered rule and cannot be correct continuations of the series.

Common Pitfalls:
Some test takers try to relate only the first letters or only the last letters and ignore the middle ones. Others may guess based on which option looks close in the alphabet without checking all three positions. A reliable strategy is to always convert to numbers and confirm that the same rule works for each position in the group.

Final Answer:
The sequence is correctly completed by the group TVW.