Correct option is (a) n = 3 to n = 1
\(\bar{V}=R_H\left(\frac{1}{n_1^2}-\frac{1}{n_2^2}\right) \)
\(\frac89\times R_H=R_H\left(\frac{n_2^2-n_1^2}{n_1^2n_2^2}\right)\)
\(\frac{(n_2-n_1)(n_2+n_1)}{n_1^2n_2^2}=\frac89\)
choosing \(n_1=1,n_2=3\)
then, \(\frac{(3-1)(3+1)}{3^2\times1^2}=\frac{2\times4}{9\times1}=\frac89\)
\(\therefore\) n = 3 to n = 1.