What caused california's population to increase in 1848 and 1849?
cotton production expanded
gold was discovered
california became a state

B. Gold was discovered

Next question is A. California applied to enter the Union as a state.

the conditions that made the byzantine empire vulnerable to attacks by the muslin turks were the sack of constantinople by western crusaders, the conquests of the sultanate of rum, presence of rival kingdoms and finally the set up of fiefdoms at the empire which were owned by the ghazis (turkish warriors).