[单选题]
Estimate the observed wavelength for the 656 nm d*s:g3radh5egvtfxf, pv*12sl em(f73c;nrline in the spectrum of a star which is p7csxf l* 3f vm; (grt1fe,v2n100 million light-years from us.
A. $653 \; nm$
B. $656 \; nm$
C. $659 \; nm$
D. $692 \; nm$
