The correct statement regarding the impact of Huayna Capac on the Inca Empire 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 significant in expanding and consolidating the Inca Empire's territories during his reign. He also made improvements in infrastructure, such as roads and agriculture, which facilitated communication and trade. However, his decision to divide the empire between his sons, Atahualpa and Huáscar, ultimately led to a civil war that weakened the empire, making it more vulnerable to Spanish conquest.