部队自备车辆或租用铁路车辆装载物资或人员挂运在货物列车上用铁路机车牵引，或铁路车辆装载军用物资用部队机车牵引时应如何计费？

A. WRED can selectively discard lower priority traffic when the interface becomes congested and can provide differentiated performance characteristics for different classes of service.
B. Resource Reservation Protocol （RSVP） and WRED cannot be configured on the same interface.
C. WRED will throttle back voice traffic only as a last resort.
D. If the average queue length is greater than the minimum threshold but less than the maximum threshold， then based on the drop probability， WRED will either queue the packet or perform a random drop.
E. WRED statistically drops more packets from low-bandwidth users than high-bandwidth users. Therefore， traffic sources that generate the least traffic are more likely to be slowed down than traffic sources that generate the most traffic.
F. WRED treats non-IP traffic as precedence 4.