Which of the following are types of flow control? (Choose three.)

A.
buffering

B.
cut-through

C.
windowing

D.
congestion avoidance

E.
load balancing

Explanation:
http://www.info-it.net/cisco/ccna/exam-tips/flow-control.php
During Transfer of data, a high speed computer is generating data traffic a lot faster than the
network device can handle in transferring to destination, so single gateway or destination device
cannot handle much amount of traffic that is called “Congestion”.
Buffering
The Technie is used to control the data transfer when we have congestion, when a network device
receive a data it stores in memory section and then transfer to next destination this process called

“Buffering”.
Windowing Whereas Windowing is used for flow control by the Transport layer.
Say the sender device is sending segments and the receiver device can accommodate only a
fixed number of segments before it can accept more, the two devices negotiate the window size
during the connection setup.
This is done so that the sending device doesn’t overflow the receiving device’s buffer.
Also the receiving device can send a single acknowledgement for the segments it has received
instead of sending an acknowledgement after every segment received.
Also, this window size is dynamic meaning, the devices can negotiate and change the window size
in the middle of a session. So if initially the window size is three and the receiving device thinks
that it can accept more number of segments in its buffer it can negotiate with the sending device
and it increase it to say 5 for example.
Windowing is used only by TCP since UDP doesn’t use or allow flow control.