Answer:
CH4
Explanation:
The ideal gas behavior of individual gases often depend on the magnitude of intermolecular interaction between the molecules of the gas as well as the presence or absence of polar bonds.
In CCl4, there are polar bonds and the presence of the more electronegative chlorine atom in the molecule and consequently a greater degree of intermolecular interaction at 400K compared to CH4 which contains only non polar bonds.
Therefore, CH4 displays greater ideal gas behavior at 400K than CCl4.
