The shortest wavelength of $H$ atom in the Lyman series is $\lambda _ { 1 }$. The longest wavelength in the Balmer series of $\mathrm { He } ^ { + }$ is:\\
(1) $\frac { 36 \lambda _ { 1 } } { 5 }$\\
(2) $\frac { 5 \lambda _ { 1 } } { 9 }$\\
(3) $\frac { 9 \lambda _ { 1 } } { 5 }$\\
(4) $\frac { 27 \lambda _ { 1 } } { 5 }$