A car moving along a level road at a constant $20\,\text{m s}^{-1}$ while acting against a constant resistive force produces a power output of $40\,\text{kW}$. What is the magnitude of the resistive force?
- A$200\,\text{N}$
- B$800\,\text{N}$
- C$2000\,\text{N}$
- D$4000\,\text{N}$