Which letter replaces the question mark ?

Concept: In a circular letter series, each sector holds a letter. Convert every letter to its alphabet position (A = 1, B = 2, ... Z = 26). Reading the sectors in a fixed rotational direction, the gap between one sector's position and the next is not constant — it grows by a fixed amount every step (for example 4, then 5, then 6, and so on). Once that growing-gap pattern is confirmed from the known sectors, apply the next gap to the last known letter to get the missing one, wrapping past Z by subtracting 26, then convert the resulting number back to a letter.

1. Read the six sectors clockwise starting from the top-left sector: M, Q, V, the blank sector, I, Q.

2. Convert the known letters to alphabet positions: M = 13, Q = 17, V = 22, I = 9.

3. Find the gap from M to Q: 17 − 13 = 4. Find the gap from Q to V: 22 − 17 = 5. The gap is growing by 1 each step, so the next gap (from V to the blank) must be 6.

4. Apply that gap to V: 22 + 6 = 28. Since the alphabet has only 26 letters, wrap around: 28 − 26 = 2, which is B.

5. Cross-check with the remaining sectors: the next gap after the blank should be 7, giving 2 + 7 = 9 = I — this matches the given I exactly. The gap after that should be 8, giving 9 + 8 = 17 = Q — this matches the final given Q exactly. Both checks confirm the missing letter.

So the missing letter is B.