Final answer:
To compare the two tions, consider the information given and the volume of the gases. The correct phrase to insert is 'VX cannot be compared to'.
Step-by-step explanation:
To correctly compare the two tions, we need to consider the information given. The forces cannot be compared without knowing the volumes of the gases, so we cannot determine which gas is greater than the other. Therefore, the correct phrase to insert on the line is b) VX cannot be compared to.