An ideal gas undergoes a thermodynamic process in which its...

Given that pressure is directly proportional to volume, we can write $P = kV$, where $k$ is a positive constant.

From the ideal gas equation, we have $PV = nRT$.

Substituting $P = kV$ into the ideal gas equation gives:
$(kV)V = nRT$
$kV^2 = nRT$
$T = \left(\dfrac{k}{nR}\right)V^2$

This equation is of the form $y = cx^2$, which represents a parabola opening upwards (towards the y-axis, which is the temperature axis).

Therefore, the graph of $T$ versus $V$ is a parabola opening towards the temperature axis.

Answer: A parabola opening towards the temperature axis