Answer:
The correct option is D.
Explanation:
The volume of cone is 12π in³.
The volume of cone is


Multiply both sides by 3.

Divide both sides by π.
..... (1)
It is given that base and height of cone and cylinder are equal.
The volume of cylinder is

Using equation (1), we get


Therefore the volume of cylinder is 36π and option D is correct.