The frequency of light emitted for the transition n = 4 to n = 2 of He+ is equal to the transition in H atom corresponding to which of the following ?

ν =Cν¯ =CRZ21n12-1n22 ν2→4(He+)=CR(4)14-116 =CR34  Given, ν2→4(He+)=νn1→n2(H)                  CR34  =  CR 1n12-1n22 From options , n1 =1 and n2=2 i.e n=2 to n=1 transition