Consider the classic TCP congestion control mechanism to answer the following questions.

$($a$)$ In slow start, what happens to a TCP sender$$s congestion window size when an acknowledgment arrives?

$($b$)$ In slow start, when does the exponential growth of TCP sending rate end?

$($c$)$ Describe how TCP Reno behaves when it receives three duplicate ACKs. Does this differ fromwhen a timer expires? If so$,$ how?