@Latexman
Thank you providing the guidance.
The answer is D if I am correct. At bubble point, Sum (KiZi) =1. At dew point, Sum (Zi/ki) = 1. Within the two phase means the temp is between bubble point and dew point temps. Thus, both Sum (KiZi) and Sum (Zi/Ki) is greater than 1.
Do you have any...