Which molecule has only london intermolecular forces?

Question

A)H20 B)HF c)GeBr4 the answer is C I know but I don't know how to determine London intert molecular........ I also don't know about premanent dipole moment and symmetrical. Please anyone can explain this in a easy way so I can undrestand?

Answer 1

GeBr4 because of the tetrehedronal shape,with Ge in the centre,has no permanent external dipole and from Br it has the ability to be externaly polarised,by influence.