Correct Answer - c
For balmer series wavelength of first line `(lambda_(1))` is give by
`(1)/(lambda_(1))=R(1)/(2^(12)-(1)/(3^(2))=(5R)/(36)`
where R is Rydberg constant
For brackett series wavelength of first line `(lambda_(2))` is given by
`(1)/(lambda_(2))=R(1)/(4^(2)-(1)/(5^(2))=(9R)/(400)`
`therefore (lambda_(1))/(lambda_(2))=(1//lambda_(2))/(1//lambda_(1))=(9R // 400)/(5R // 36)=0.162`