Viacom (NasdaqGS: VIAB - news ) fell 7.5 percent, 21st Century Fox lost 7.0 percent, CBS shed 4.6 percent and Comcast dropped 4.7 percent.
Utilize the input text as a context reference, choose the right relationship between 'Viacom' and 'CBS' from the options.
Options: stock exchange, original broadcaster, owned by, distribution format