The most accurate response is:
Huayna Capac expanded the reach of the empire, improved infrastructure, and split the empire between two sons, leading to a civil war.
Huayna Capac was a significant ruler of the Inca Empire, known for his military conquests that expanded the empire's territory. He also invested in improving infrastructure, such as road networks, which facilitated communication and trade across the vast empire. However, his decision to divide the empire between his two sons, Atahualpa and Huáscar, ultimately led to a civil war that weakened the empire and made it more vulnerable to Spanish conquest.