Answer
An Elliptical cone along $y$-axis as represented by $\bf{Graph(h)}$
Work Step by Step
Given: $x^2+4z^2=y^2$ ...(1)
Re-write as:
$\dfrac{x^2}{1}+\dfrac{z^2}{(1/2)^2}=\dfrac{y^2}{1}$ ...(2)
Hence, the equation (2) shows a graph for an Elliptical cone along $y$-axis as represented by $\bf{Graph(h)}$
