Which Cisco IOS multipoint video conferencing profile is also known as best-effort video on the Cisco Integrated Router…?

Which Cisco IOS multipoint video conferencing profile is also known as best-effort video on the Cisco
Integrated Router Generation 2 with packet voice and video digital signal processor 3?

A.
homogeneous

B.
guaranteed-audio

C.
rendezvous

D.
heterogeneous

E.
flex mode video

Explanation:
Three types of video profiles are supported: homogeneous conferences (video
switching), heterogeneous conferences (video mixing), and guaranteed audio conferences (besteffort video).
As the name suggests, when Guaranteed Audio Conferences is configured, the system attempts to
display video for all participants; however, it does not guarantee that the video of all participants is
displayed. For those participants whose video is not displayed, participants are downgraded to
audio-only and the profile guarantees preservation of the audio portion of the call. This option gives
you added flexibility because the DSPs are not all reserved when the profile is created; the system
attempts to reserve them when this profile is activated with an actual conference. For example:
dspfarm profile 1 conference video guaranteed-audio
codec h264 vga
codec h264 4cif

http://www.cisco.com/c/en/us/products/collateral/unified-communications/voice-videoconferencing-isr-routers/qa_c67-649850.html