**Correct option is: (C) 301.44 Cu. m**

Diameter of cone is 2r = 12 m

\(\therefore\) Radius of cone is r = 6 cm and height of the cone is h = 8 m.

\(\therefore\) Volume of heap = volume of cone

= \(\frac 13 \) \(\pi r^2\)h = \(\frac 13 \) \(\times\)3.14 \(\times\)6 \(\times\) 6 \(\times\)8

= 96 \(\times\) 3.14

= 301.44 \(m^3\)

Hence, the volume of the heap is 301.44 cubic metre