Complete the following series.
Z1, Y4, X9, _____

Correct option is D

Given Series: Z1, Y4, X9, _____
Logic:
The first letters are following a backward alphabetical order: Z, Y, X, W.
The numbers are squares of consecutive integers: 1², 2², 3², 4².

Z (1st letter) → Y (2nd letter) → X (3rd letter) → W (4th letter).
The number sequence follows the squares: 1² = 1, 2² = 4, 3² = 9, 4² = 16.
Final Answer: W16
Final Correct Option: (A) W16