The Wavelength of the Red-Pink Line Emitted by a Laboratory

The wavelength of the red-pink line emitted by a laboratory sample of excited hydrogen is 656 nm. Taking a spectrum of a glowing nebula, you find that the same red-pink line of hydrogen appears at 662 nm. You conclude that the nebula

A) is 1% hotter than hydrogen in the laboratory sample.
B) is moving toward us at about 1% the speed of light.
C) is 1% cooler than hydrogen in the laboratory sample.
D) is moving away from us at about 1% the speed of light.