Refer to the Exhibit.
What would happen if the guaranteed-rate command is removed from the configuration shown in
the exhibit?
A.
The logical interface gets a minimal bandwidth reservation.
B.
The minimum-rate command should be configured instead.
C.
The logical interface receives no bandwidth constraints.
D.
The transmit-rate command should be configured instead.
Explanation:
http://www.juniper.net/documentation/en_US/junos13.2/topics/usage-guidelines/cos-providing-a-guaranteed-minimum-rate.html
shaping rate (the peak information rate [PIR]), guaranteed rate (the committed information rate [CIR] on these interfaces), scheduler maps (assigning queues and resources to traffic)
If you do not specify a shaping rate or a guaranteed rate, the logical interface receives a minimal delay-buffer rate and minimal bandwidth equal to four MTU-sized packets.
From the URL provided by jslaven.
There is a table which describe more easier. Check the table1.
First scenario, you can see the answer