The Egyptian and Kush civilizations shared similar: styles of art and architecture. Option three is correct.
The most architectural building in Egypt is undoubtedly the Pyramid and the Spynx. In the Kingdom of Kush, many archeologist found the residual architecture that prove the presence of Nubian Pyramids, which are also used for burial purpose of the Kush' nobles.
The Kingdom of Kush was an ancient civilization in Africa. It is often referred to as Nubia and had close ties to Ancient Egypt.