A company has fixed costs amounting to $8000$, and these will rise only once production goes above $40000$ units. It produces and sells $20000$ units of one product. Each unit sells for $10$ and has a contribution to sales ratio of $40\%$. By what amount does profit rise if it produces and sells $30000$ units?
- A$32000$
- B$40000$
- C$92000$
- D$120000$