A Blue Line in the Spectrum of the Hydrogen Atom $\lambda$

Multiple Choice

A blue line in the spectrum of the hydrogen atom has a wavelength $\lambda$ = 486 nm.In the hydrogen-atom spectrum emitted by a distant galaxy,this line is observed on Earth at $\lambda$ = 550 nm.With what speed is this galaxy receding from us? (The speed of light is 3.0 $\times$ 10⁸ m/s.)

A) 1.31 $\times$ 10⁷ m/s
B) 1.13 $\times$ 10⁸ m/s
C) 2.65 $\times$ 10⁸ m/s
D) 3.49 $\times$ 10⁷ m/s
E) 3.95 $\times$ 10⁷ m/s