Consider two identical rigid containers filled with the same mixture of oxygen and helium at constant temperature. The total pressure of the gases in each container is initially the same. By decreasing the volume of container (1), the pressure of the He and O2 mixture was doubled. The pressure in container (2) was also doubled by pumping some argon into it. Did the partial pressure of He, pHe, change in these two containers?

a) pHe increased by a factor of 2 in container (1) but did not increase in container (2).

b) pHe increased by a factor of 2 in container (2) but did not increase in container (1).

c) pHe increased by a factor of 2 in both containers.

d) pHe increased in both containers by a factor equal to the fraction of He in the gas mixture.

e) pHe remained unchanged in both containers.