Suppose that light from an astronomical object is emitted with a rest wavelength of 500 nm is observed to have a wavelength of 600 nm. What is the speed of the object and in what direction is it moving?
a) -1/6c, toward observer
b) -1/5c, away from observer
c) -1/5c, toward observer
d) -1/6c, away from observer
e) -5/6c, toward observer