A rubber band is extended by suspending weights from it, and the results are used to draw a force-extension graph. What is the most suitable estimate of the strain energy stored in the rubber band when its extension is $30\,\text{cm}$?
- A$1.8\,\text{J}$
- B$2.6\,\text{J}$
- C$5.1\,\text{J}$
- D$200\,\text{J}$