Let A be a server, and B be a sensor node, and assume we want them to have bidirectional communication among each other. The sensor has low buffering capacity, while the server has high buffering capability. Is it possible that in the data link layer they use they the Go Back N protocol for the A -> B direction, and the Selective Repeat protocol for the B -> A direction? a. Yes. If Go Back N is used in the A->B direction, then the sender A has to do the buffering for that direction. In Selective Repeat the receiver has to do the buffering, but in the B->A direction A is the receiver. That is, in both directions A will have to do the buffering, which is possible, since the server has the capacity for that. b. No, because Selective Repeat needs high buffering, and only one of them has the capacity for that, not both. c. No, because they will be confused to use two different protocols in the two directions