In each of the following questions there is a series of letters with one term…

Concept: In a letter-series problem built from fixed-length letter groups, check two separate patterns together — the skip between the letters inside each group, and the skip that links the starting letter of one group to the starting letter of the next.

1. Assign each letter its position in the alphabet (a = 1, b = 2, … z = 26). Every given group here steps by 2 internally: p(16) r(18) t(20); b(2) d(4) f(6); h(8) j(10) l(12); n(14) p(16) r(18).

2. Track only the starting letters of the groups in order: p(16), ?, b(2), h(8), n(14). From b to h the jump is +6, and from h to n the jump is also +6, so the starting letters advance by a fixed +6 each time (wrapping past z back to a).

3. Apply that same +6 jump from p to find the missing starting letter: p(16) + 6 = 22 = v. Checking forward, v(22) + 6 = 28, which wraps to 28 − 26 = 2 = b — exactly the next group's starting letter given in the series.

4. Build the missing group using the +2 internal skip starting from v(22): v(22), x(24), z(26), giving v x z.

Cross-check: v x z satisfies both patterns at once — internally v → x → z steps by 2 like every other group, and externally the starting letters p → v → b → h → n each advance by a fixed +6 around the alphabet. No other combination of letters satisfies both checks together, so v x z is the missing term.