Answer:
The next letter in the sequence is T.
Step-by-step explanation:
The pattern in the sequence A, Z, B, Y, C, X, D is that it alternates between letters in the alphabet and their reverse order counterparts, moving sequentially:
A (1st letter) and Z (26th letter)
B (2nd letter) and Y (25th letter)
C (3rd letter) and X (24th letter)
D (4th letter)
Following this pattern, the next letter after D (4th letter) would be the reverse counterpart of E (5th letter), which is T (20th letter).
Therefore, the next letter in the sequence is T.