Answer: Third option.
Step-by-step explanation:
For this exercise it is important to remember that, by definition, a Joint variation is that variation in which one variable depends on two or more variables and there are a direct relation between these variables.
In this case, you have the following equation given in the exercise:
[tex]V=r^2h[/tex]
Let's assume that "r" and "h" are variables.
You can identify that:
So, based on this, the variation can be read as:
"V" varies jointly with the square of "r" and "h".
Therefore, you can conclude that the given variation is: Joint.