[单选题]
Estimate the observed wavelength for the 656 nd.vxxu m 60q.em line in the spectrum of a cfj :j0 rtik*20i5 mapj0a9y istar which is 100 million light-years fro 5akc*ijtm i00piy:j a2fj09r m us.
A. $653 \; nm$
B. $656 \; nm$
C. $659 \; nm$
D. $692 \; nm$
