Astronomy Question ?

[Johnny Drama]

if the rest wavelength of a certain line is 600 nm, but we observe it at 594 nm, then
A) the source is spinning very rapidly, at 1% of the speed of light
B) the source is approaching us at 1% of the speed of light
C) the source is receding from us at 10% of the speed of light
D) the source is approaching us at .1% of the speed of light
E)the source is getting 1% hotter as we watch

 

[Harley Drive]

G) none of the above are certain

 

[Kayla C]

F all of the above