In a letter-number series, treat the letters and the number separately and look for a constant step in each position. Listing the terms — LTP25, MUQ36, NVR47, OWS58, ? — we track each of the three letters and the two-digit number across the terms.

First letter: L → M → N → O → …, each moving +1 in the alphabet, so the next is P.

Second letter: T → U → V → W → …, each +1, so the next is X.

Third letter: P → Q → R → S → …, each +1, so the next is T.

Number: 25 → 36 → 47 → 58 → …, increasing by a constant +11 each time, so the next is 58 + 11 = 69.

Combining the four independently advanced parts gives PXT69, which is the correct answer.

The wrong choices arise from breaking just one of these steps: writing U instead of T for the third letter (as in PXU69 or PXU68) mistakenly advances S by two places, and using 68 instead of 69 (as in PXT68 or PXU68) breaks the steady +11 number pattern. Keeping every position at its own constant step yields PXT69.