Which of the characteristics below is associated with the (QoS) Integrated Services Model?

A.
QoS classified at layer 3 using IP precedence or DSCP.

B.
Guaranteed rate service.

C.
Implemented using FIFO queues.

D.
All traffic has an equal chance of being dropped.

Explanation:
Cisco IOS QoS includes the following features that provide controlled load service, which is
a kind of integrated service:
Resource Reservation Protocol (RSVP) can be used by applications to signal their QoS
requirements to the router.
Intelligent queuing mechanisms can be used with RSVP to provide the following kinds of
services:
Guaranteed Rate Service, which allows applications to reserve bandwidth to meet their
requirements. For example, a Voice over IP (VoIP) application can reserve 32 Mbps end to
end using this kind of service. Cisco IOS QoS uses weighted fair queuing (WFQ) with RSVP
to provide this kind of service.
Controlled Load Service, which allows applications to have low delay and high throughput
even during times of congestion. For example, adaptive real-time applications such as
playback of a recorded conference can use this kind of service. Cisco IOS QoS uses RSVP
with Weighted Random Early Detection (WRED) to provide this kind of service.
Reference:
http://www.cisco.com/en/US/products/sw/iosswrel/ps1831/products_configuration_guide_ch
apter09186a008007ff07.html#1000946