ANS:D - none of these.

The gravimetric composition of a vapor-saturated gas refers to the proportion of each component in the gas phase relative to its mass. This composition is primarily determined by the nature of the gas and the temperature, but it is indeed independent of the total pressure. Here's why:

1. Nature of the gas and the liquid: The composition of a vapor-saturated gas depends on the properties of the substances involved, including their vapor pressures at a given temperature. Different substances have different vapor pressures, which affect their proportions in the gas phase.
2. Temperature: The temperature influences the vapor pressure of each component in the system. As the temperature changes, the vapor pressures of the substances also change, leading to variations in their proportions in the vapor phase.
3. Total pressure: The total pressure affects the point at which the gas becomes saturated with vapor. However, it does not directly affect the composition of the vapor-saturated gas once equilibrium is reached. The composition is determined solely by the nature of the substances and the temperature at that equilibrium condition.