An atom of mass m, initially at rest, resonantly absorbs a photon. It makes a transition from the ground state to an excited state and also gets a momentum kick. If the difference between the energies of the ground state and the excited state is \(\hbar \Delta\), the angular frequency of the absorbed photon is closest to
1
\(\Delta\left(1+\frac{3}{2} \frac{\hbar \Delta}{m c^2}\right)\)
2
\(\Delta\left(1+\frac{1}{2} \frac{\hbar \Delta}{m c^2}\right)\)
3
\(\Delta\left(1+\frac{\hbar \Delta}{m c^2}\right)\)
4
\(\Delta\left(1+2 \frac{\hbar \Delta}{m c^2}\right)\)