Suppose that we're doing pipelining, with cumulative acknowledgements, and that our window size is 10 packets. A sender sends a window of 10 packets, but packet 3 is dropped. a. What's the acknowledgement number of the acknowledgment sent when packet 4 is received? b. What two pieces of information does the sender know when this acknowledgement is received? c. What does the sender then do if we're doing: i. Selective Repeat ii. Go Back N In what scenario(s) might Selective Repeat be preferable to Go Back N? In what scenario(s) might Go Back N be preferable to Selective Repeat