Elaborate drainage system
The harappan civilization is also known as the Indus river valley civilization. known as the earliest producers of cotton, the city featured an elaborate drainage system, which could have been necessitated by prosperity and effort to control the outbreak of river-line diseases.
Answer: A.)
Explanation: The Columbian exchange, also known as the Columbian interchange, named for Christopher Columbus, was the widespread transfer of plants, animals, culture, human populations, technology, and ideas between the Americas, West Africa , and the Old World in the 15th and 16th centuries.
