The volume of a sphere is 2145 1121 c m^3. Its radius is equal to :

Answer: Option B

$$\begin{array}{rl}& \frac{4}{3}\times \frac{22}{7}\times r^3=\frac{45056}{21}\\ & \Rightarrow r^3=\left(\frac{45056}{21}\times \frac{3}{4}\times \frac{7}{22}\right)\\ & \Rightarrow r^3=512\\ & \Rightarrow r=\text{root}3\text{of}512\\ & \Rightarrow r=8cm\end{array}$$