The spread of Islam quickly over a short period of time was most likely due to which of the following factors? A. Invasions and conquest B. Trade and commerce C. Marriage and Kinship D. Education and Scholarship​

All of the above. Invasion and conquest by the Ottomans and modern terrorists. Trade and commerce along the Silk Road. Marriage and kinship? look ar Bosnia and Serbia. Education (false as it might be) take a look at Andrew's University in Southern Michigan and Marquette University, a privet Christian school and Jesuit school respectively. Both have high Muslim populations from Saudi Arabia, Yemen, Syria and other predominately Muslim nations.

c. troops marched forward in close formation against newer, more accurate weapons