Correct option is : (1) \(\frac{5}{27}\)
\(\frac{1}{\lambda} = Rz^2 \left( \frac{1}{n_1^2} - \frac{1}{n_2^2}\right)\)
\(\frac{1}{\lambda _1} = Rz^2\left( \frac{1}{1}- \frac{1}{4}\right)\)
\(\frac{1}{\lambda _2} = Rz^2 \left( \frac{1}{4} - \frac{1}{9}\right)\)
\(\frac{\lambda _1}{\lambda _2} = \frac{5}{27}\)