Explanation:

In order to ensure the statement that holds ' W > Z' and ' Y > Z' definitely true, we
have to check all the options one by one.
For option A:
W > X > U = Z < H ≤ Y
Here, the common sign between W and Z is '>', thus it follows W > Z.
The common sign between Z and Y is also '<' , thus it follows Z < Y or Y > Z.
For option B:
W ≥ X = U > Z ≤ H < Y
Here also, the common sign between W and Z is '>', thus it follows W > Z.
The common sign between Z and Y is also '<' , thus it follows Z < Y or Y > Z.
For option C:
W = X > U ≥ Z < H < Y
Here again, the common sign between W and Z is '>', thus it follows W > Z.
The common sign between Z and Y is also '<' , thus it follows Z < Y or Y > Z.
Since all the three expressions hold the given conclusions true, option D "all of
the above" is correct.
Hence option D is correct.