Neutral nations included: 1 switzerland2 spain3 lower slobovia4 scandinavia5 holland6 serbia(multi choice)

the answer is a) to be able to obey them.

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).