I want to know the answer to the following question:
What has caused Stokavian to become more widely spoken?
All the background I'm provided with is that "In the past, Chakavian and Kajkavian dialects were spoken on a much larger territory, but have been replaced by Štokavian during the period of migrations caused by Ottoman Turkish conquest of the Balkans in the 15th and the 16th centuries.". Is that enough to answer the question?