Under the rule of huayna capac, the inca empire a. declined in power and was conquered by the spanish b. discouraged trade and regional interaction c. reached the height of its power and doubled in size d. introduced taxes and divided its territory into administrative areas

Under the rule of Huayna Capac, the Inca empire reached the height of its power and doubled in size. The correct option among all the options that are given in the question is the third option or option "c". I hope that this is the answer you were looking for and it has come to your help.