Between the nucleus and electrons gravitational force of attraction is present.

Gravitational force is the force of attraction between any two masses.

Electrons and the nucleus will also exert a gravitational force on each other as they have mass. However, this force will be very small, almost negligible as the mass of the electron and nucleus is very small.

As the electrons and nucleus are charged, they exert electrostatic force on each other which is way stronger than the gravitational force. However, this does not mean that the gravitational force is not exerted between the nucleus and electrons.

Hence option A will be the correct answer.