A series is given with one term missing. Choose the correct alternative from the given options that will complete the series ZXV, USQ, PNL, ?

Introduction / Context:
This is a three letter alphabet series where all letters in each term follow a descending pattern. The student must identify how the positions of the letters shift from term to term and then use this observation to find the missing three letter group. Handling multiple letters moving in parallel is an important skill in series based reasoning questions.

Given Data / Assumptions:

• The given series is ZXV, USQ, PNL, ?
• Each term has three uppercase letters.
• We use alphabetical positions A = 1 through Z = 26.
• The same rule should apply to all three positions across terms.

Concept / Approach:
We treat each letter position (first, second, and third) as its own sub series. We compute the differences between terms in terms of positions. If we see a constant negative difference, we continue that pattern to get the letters for the missing term. The structure suggests a steady backward movement in the alphabet.

Step-by-Step Solution:
Step 1: Write the first letters: Z, U, P. Step 2: Their positions are Z = 26, U = 21, P = 16. Each step is minus 5: 26 to 21 and 21 to 16. Step 3: Apply minus 5 again: 16 minus 5 equals 11, which corresponds to K. So the first letter of the missing term is K. Step 4: Now write the second letters: X, S, N. Step 5: Their positions are X = 24, S = 19, N = 14. Again, each step is minus 5. Step 6: Subtract 5 from 14 to get 9, which corresponds to I. So the second letter is I. Step 7: Finally, consider the third letters: V, Q, L. Step 8: Their positions are V = 22, Q = 17, L = 12. Each step is again minus 5. Step 9: Subtract 5 from 12 to get 7, which corresponds to G. So the third letter is G. Step 10: Therefore, the missing term is KIG.

Verification / Alternative check:
We can summarise the pattern as a constant shift of minus 5 in every letter position. Z (26) to U (21) to P (16) to K (11), X (24) to S (19) to N (14) to I (9), and V (22) to Q (17) to L (12) to G (7) all follow this rule. No other option fits such a consistent minus 5 movement in all three positions.

Why Other Options Are Wrong:
MJH, JHF, and KJI do not match the minus 5 pattern when compared with PNL. For instance, from P (16) to M (13) is minus 3, not minus 5. Similarly, the second and third letters in those options break the required pattern. The none of these option is incorrect, because KIG matches the observed rule exactly.

Common Pitfalls:
One common mistake is to analyse only one letter position and choose an answer that works partially. Another is to miscount backwards in the alphabet, especially when crossing from earlier letters. Carefully writing the positions and checking all three letters helps prevent these errors.

Final Answer:
The three letter group that completes the series is KIG.