A manometer is filled with mercury of density $14\,000\,\text{kg m}^{-3}$. It is linked to a gas supply, and the difference between the mercury levels is $72\,\text{mm}$. Atmospheric pressure is $100\,\text{kPa}$. The gravitational field strength $g$ is $10\,\text{N kg}^{-1}$. What is the pressure of the gas supply?
- A$90\,\text{kPa}$
- B$99\,\text{kPa}$
- C$110\,\text{kPa}$
- D$200\,\text{kPa}$