Alphabet triplets with constant internal gaps – find the next group: DHL, PTX, BFJ, ?

Introduction / Context:
Each term is a three-letter block with a fixed internal structure. The starting letter of each block shifts systematically between blocks. Recognizing both the within-block pattern and the between-block starting-letter pattern yields the answer.

Given Data / Assumptions:

• Blocks: DHL, PTX, BFJ, ?
• English alphabet indexing A=1 … Z=26.

Concept / Approach:
Inside each block, letters are spaced by +4 positions: e.g., D(4) → H(8) → L(12). Verify this for the other blocks and then analyze the sequence formed by the first letters of each block.

Step-by-Step Solution:
Check internal pattern: DHL is 4, 8, 12 (+4, +4). PTX is 16, 20, 24 (+4, +4). BFJ is 2, 6, 10 (+4, +4). So the triplet rule is consistent.First letters: D(4) → P(16) → B(2) → ?The movement among first letters alternates by +12, then −14. Continuing the same two-step rhythm, add +12 again: 2 + 12 = 14 → N.Now apply the +4, +4 internal rule starting at N(14): N(14), R(18), V(22) → “NRV”.

Verification / Alternative check:
Writing starts as 4, 16, 2, 14 reveals a repeating +12, −14 cycle. Combined with the constant +4 internal jumps, “NRV” is the only block that satisfies both conditions.

Why Other Options Are Wrong:

• CGK, KOS, RVZ violate either the start-letter cycle or the +4 within-block spacing.
• Even near-looking groups fail when converted to numeric positions and checked for +4 consistency.

Common Pitfalls:

• Spotting the +4 spacing but overlooking the pattern of the starting letters across blocks.

Final Answer:
NRV