Context: The early 1990s marked the softening of urban R&B at the same time alternative rock emerged and traditional pop saw a significant resurgence. This in part led to a widening of the market, not only allowing to cater to more niche markets, but it also became customary for artists to make AC-friendly singles.

Question: The resurgence of traditional pop was one of the factors that led to what change in the music market?

Answer: widening of the market