What comes next? ZYX, YXW, XWV, WVU, ?

Correct — A.
Rule: three consecutive letters running backwards, each term starting one letter earlier.

First letters: Z, Y, X, W → next is V.
Inside each term the letters count back by one: Z-Y-X, W-V-U.

From V: V, U, T = VUT → option (a).

Why the others are wrong

• (b)
  UVT — UVT starts with U, not V, and runs U → V forwards. The first letters fall Z, Y, X, W, so the next term begins with V.
• (c)
  VTS — VTS starts correctly with V but skips U. The letters inside each term are consecutive, so V is followed by U, then T.
• (d)
  TUV — TUV has the right three letters in the wrong direction. The series counts backwards (Z → Y → X), so the term reads V, U, T.

Read the series one position at a time. The first letters run Z, Y, X, W, falling by one each step, and the second and third letters fall by one as well.

It also reads as a chain: the last two letters of each term open the next (ZYX → YXW). So WVU hands on VU, and one more step back adds T.

Key facts

• Reverse alphabet from Z: Z, Y, X, W, V, U, T.
• Positions: T = 20, U = 21, V = 22, W = 23.
• In an overlapping series, the last two letters of one term are the first two of the next.

Common traps

• Picking TUV for its letters without checking their direction
• Skipping a letter, as in VTS, when the letters inside each term are consecutive

No directly related past PYQ was found.