If m - 5n = 2, then the value of (m3 - 125n3 - 30mn) is?

Answer: Option C

$$\begin{array}{rl}& \text{Given, }m-5n=2\\ & \text{Find, }{m}^3-125n^3-30mn\\ & \Rightarrow m-5n=2\\ & \left(\text{Cubing both sides}\right)\\ & \Rightarrow {\left(m-5n\right)}^3=2^3\\ & \Rightarrow m^3-125n^3-3m\times 5n\left(m-5n\right)=8\\ & \Rightarrow m^3-125n^3-15mn\times 2=8\\ & \Rightarrow m^3-125n^3-30mn=8\end{array}$$