Answer:
radius is the other quantity needed, which appears listed as option C in the list of possible answers.
Explanation:
Recall that the volume of a cone is given by the formula:
where B is the area of the base:
with R being the cone's radius at the base, and H the cone's height.
The formula for the surface area of the cone also needs the size of the radius.
Therefore, the radius is the other needed quantity.