Which letter replaces the question mark ?

Concept: In an alphanumeric series of this kind, the letter placed between two numbers is not a word — it stands for its position in the alphabet (A = 1, B = 2, … Z = 26), and that position is produced by applying ONE fixed arithmetic rule to the digits of the two flanking numbers in the same row.

1. Find the rule from a solved row. Row 1: 53 and 49. Left digit-gap = |5−3| = 2. Right digit-gap = |4−9| = 5. Product = 2 × 5 = 10 → the 10th letter, J, matches the letter shown.

2. Confirm with Row 2: 82 and 37. Left digit-gap = |8−2| = 6. Right digit-gap = |3−7| = 4. Product = 6 × 4 = 24 → the 24th letter, X, matches the letter shown.

3. Confirm with Row 3: 36 and 15. Left digit-gap = |3−6| = 3. Right digit-gap = |1−5| = 4. Product = 3 × 4 = 12 → the 12th letter, L, matches the letter shown.

4. Apply the confirmed rule to the last row: 14 and 98. Left digit-gap = |1−4| = 3. Right digit-gap = |9−8| = 1. Product = 3 × 1 = 3.

5. The 3rd letter of the alphabet is C.

Cross-check: the same digit-gap-product rule exactly reproduces all three given letters (J, X, L), so applying it to the final row is reliable, and the resulting letter is also the only offered option equal to the 3rd alphabet position.