Final answer:
The type of mud-brick structure used in Nubian architecture is called a deffufa. It served as a religious structure and was made of mud bricks.
Step-by-step explanation:
The type of mud-brick structure that was used in Nubian architecture is called a deffufa. The deffufa was a type of building that served as a religious structure and was found in ancient Nubia, located in present-day Sudan. It was typically made of mud bricks and had a distinctive shape with sloping walls.
Learn more about Nubian architecture