Which answer choice describes the noble gases?

The answer for #3 is c but i don't know why

The bond energy for the van der waals bond between two helium atoms is 7.9×10−4ev. assuming that the average kinetic energy of a helium atom is (3/2)kbt, at what temperature is the average kinetic energy equal to the bond energy between two helium atoms

What is the most important factor in determining climates.