Which of the following contains sacred hindu writings?
a. the upanishads and the vedas
b. the kshatriya and the upanishads
c. the atman and the vedas
d. the vedas and the yoga

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).