Containers a, b, and c have the same volume and are at the same temperature. The pressures of the gases are 150 kpa in container a, 300 kpa in container b, and 50 kpa in container c. What is the total pressure when the three gases are combined in container b?
a. 300 kpa
b. 50 kpa
c. 500 kpa
d. 250 kpa