Answer
$\bf{Graph{(VI)}}$
Work Step by Step
The parametric equations of a circle having radius $r$ are; $x=r \cos t ; y =r \sin t$
Here, we have $x= t \cos t , y= \sin t , z=\dfrac{1}{1+t^2}$
We see that $x$ and $y$ look like a circle when we look down from a top view with a high z-value.
The parametric equation $z=\dfrac{1}{1+t^2}$ shows that $z$ is always positive.
This matches with $\bf{Graph{(VI)}}$.
