A sample of helium gas at [Conditions A] and [Conditions B] is combined with a sample of neon gas at [Conditions C] and [Conditions D]. The temperature is kept constant. Which of the following statements about combining the gases is correct?
a) The pressure of the resulting mixture is the sum of the pressures of the individual gases.
b) The volume of the resulting mixture is the sum of the volumes of the individual gases.
c) The partial pressures of the individual gases remain constant.
d) The total number of moles of gas in the resulting mixture decreases.