Spiral arms result from density waves in a disk galaxy. Starformation occurs in these arms. As the material in a galaxyinteracts with a spiral density wave, clouds compress and dustlanes form. Then, the dense gas clouds ignite with star formation.What is the evidence in this image that supports the claim that thestars are moving faster than the density waves?
A. Bright stars can be found on the leading edges of thearms.
B. Bright stars are only found on the trailing edges of thearms.
C. Dust clouds form on the leading edges of the arms.
D. Ionization nebulae form on the trailing edges of thearms.
