A series of lines in the spectrum of atomic H lies at wavelengths 656.46 , 486.27 , 434.17 , 410.29 mm. what is the wavelength of next line in this series?

Question

$(a)\;493.3 nm\qquad(b)\;397.2nm\qquad(c)\;593.4nm.\qquad(d)\;392.3nm$