Which of the following statements is true?
a. Recently, many enterprises have incorporated reverse logistics with conventional forward-only logistics to form a closed-loop supply chain.
b. Very few enterprises have incorporated reverse logistics with conventional forward-only logistics.
c. Within a close-loop supply chain, the logistics between the distribution/collection center and the customers is the least complicated part.
d. Within a close-loop supply chain, the logistics between the distribution/collection center and the customers is irrelevant.