A heap of wheat is in the form of a cone whose diameter is 10.5 m and height is 3 m. Find its volume. The heap is to be covered by canvas to protect it from the rain. Find the area of the canvas required.
[Assume π=22/7]

A. 89.825 m²
B. 79.825 m²
C. 19.825 m²
D. 99.825 m²