Correct option is A
Z is the tallest.
U is shorter than Y but taller than X: This means the order for Y, U, and X is Y > U > X.
X is taller than V: This means X > V.
Arrange the friends by height:
Z is the tallest.
From the second point: Y > U > X.
From the third point: X > V.
Thus, the order from tallest to shortest is:
Z > Y > U > X > V.
The third tallest is U.
Correct answer is (a) U