Correct Answer - C
After obsorbing a photon of energy 12.1eV electron jumps from ground state `(n=1)` to second excited state `(n=3) . "Therefore"` change in angular ,brgt momentum `DeltaL=L_(3)-L_(1) =3(h/(2pi)) -h/(2pi)=h/pi`
` =(6.6xx10^(-34))/(3.14)js=2.11xx10^(34)Js`