An ideal gas differs from a real gas in that the molecules of an ideal gas a have a molecular weight of zero b have appreciable molecular volumes c have an average molecular mass d have no attraction for one another e have no kinetic energy

An ideal gas differs from a real gas in that the molecules of an ideal gas have no attraction for one another. 
An ideal gas is defined as one in which collisions between atoms or molecules are perfectly elastic and in which there are no inter-molecular attractive forces. A real gas on the other hand is a gas that does not behave as an ideal gas due to interactions between gas molecules. Particles in a real gas have a real volume since real gases are made up of molecules or atoms that typically take up some space even though they are extremely small. 

Ithink the answer is a or d.