Flask X holds $5\,\text{dm}^3$ of helium at a pressure of $12\,\text{kPa}$, while flask Y holds $10\,\text{dm}^3$ of neon at a pressure of $6\,\text{kPa}$. When the flasks are connected and the temperature is kept constant, what final pressure is reached?
- A$8\,\text{kPa}$
- B$9\,\text{kPa}$
- C$10\,\text{kPa}$
- D$11\,\text{kPa}$