A lump of modelling clay is transferred from a small measuring cylinder into a large measuring cylinder with twice the diameter. The reading on the small measuring cylinder decreases by $20\,\text{cm}^3$. By how much does the reading on the large cylinder increase?
- A$10\,\text{cm}^3$
- B$20\,\text{cm}^3$
- C$40\,\text{cm}^3$
- D$80\,\text{cm}^3$