Why did independent stations finally become a viable competitor to broadcast networks in the 1980s?
a. Cable systems allowed UHF stations (the band most independent stations were on) to appear identical to VHF stations.
b. The emergence of a strong syndication market provided inexpensive programming options to independent stations through barter deals.
c. The loosening of ownership rules led to a boom in station construction, so there were far more independent UHF stations.
d. All the above.