The correct answer is D) As a record-keeping system to keep track of economic information.
Scholars think the Inca used the Quipu as a record-keeping system to keep track of economic information.
The Quipu was a tool used by the Incas to keep records and transmit information to other villages. They did not have a writing system. They used strings of different sizes and colors and tied some knots to track information or keep economic accounts. The Quipu could contain hundreds of thousands of strings.