I want to know the answer to the following question:
During what period was adult contemporary its most commercially successful?
All the background I'm provided with is that "Soft rock reached its commercial peak in the mid-to-late 1970s with acts such as Toto, England Dan & John Ford Coley, Air Supply, Seals and Crofts, America and the reformed Fleetwood Mac, whose Rumours (1977) was the best-selling album of the decade.". Is that enough to answer the question?