A piston in a gas supply pump has a cross-sectional area of $400\,\text{cm}^2$ and travels a distance of $25\,\text{cm}$ in one stroke. The pump pushes the gas against a constant pressure of $3000\,\text{Pa}$. Calculate the work done by the piston in one stroke.
- A$30\,\text{J}$
- B$3.0 \times 10^3\,\text{J}$
- C$3.0 \times 10^5\,\text{J}$
- D$3.0 \times 10^7\,\text{J}$