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 C. reached the height of its power and doubled in size.

Explanation:

Huayna was the son of Topa Inca Yupanqui (1471-1493), an Incan King who drove a massive development of the Incan Empire, spreading it towards the Tahuantinsuyu or place that is known for four quarters. The recently vanquished space was colossal to the point that it scattered profound into the Amazon backwoods.