Final answer:
The expression equal to xz is D. 2x^3/y.
Step-by-step explanation:
To find the value of xz, we can rearrange the given equation: xyz^2 = 2z^4. Dividing both sides by z^2 gives us xy = 2z^2. If we divide both sides by y, we get xz = 2z^2/y. Therefore, the expression equal to xz is D. 2x^3/y.