Statement-A :Van De Graaff generator is a machine that can build up high voltages of the order of a few million volts.

Statement-B :In the absence of external electric field, in a non-polar molecule, the centres of positive and negative charges coincide.

Van de Graff generator is an electrostatic generator which is devised to produce very high voltage by means of an endless belt collecting electrostatic charge from a source and transferring it to a large isolated metal sphere on which a large change accumulates.

The center of mass of positive charges coincides with the center of mass of the negative charges, in the molecule. In its normal state (i.e., in the absence of any external force, esp electric field), each molecule has zero dipoles.