B

问题如下：

Which of the following best describes the principles of a circular economy?

选项：

A.Designing out waste and pollution, keeping materials in use, and regenerating natural systems

B.Ensuring that all products are returned to manufacturers to reuse component parts

C.Producing goods only for consumption by customers in the manufacturer’s domestic market

解释：

A is correct. The circular economy is a broad economic model based on three principles: (1) designing out waste and pollution, (2) keeping materials in use, and (3) regenerating natural systems.