Doppler Shifted Hydrogen Absorption Lines Are Seen in the Spectrum

Multiple Choice

Doppler shifted hydrogen absorption lines are seen in the spectrum of a star. The hydrogen line at 656.28 nm is seen to be shifted to 656.08 nm. How large is the fractional shift in wavelength?

A) about 0.03 (3 × 10-2)
B) about 0.0003 (3 × 10-4)
C) about 0.2
D) about 0.000003 (3 × 10-6)