Container A contains the ideal gas at a pressure of 5 x 10^5 Pa and a temperature of 300 K. The container is connected by a thin tube (and a closed valve) to container B which has four times the volume of container A. Container B stores the same ideal gas at a pressure of 5 x 10^5 Pa and a temperature of 400 K. Then the valve is opened to equalize the pressure between the containers, but the temperature of each container is maintained. What is the pressure of the container?
a. 2 x 10^5 Pa
b. 1 x 10^5 Pa
c. 1 x 10^6 Pa
d. 2 x 10^6 Pa
e. 3 x 10^6 Pa