$18$

$1$ point

Suppose an application uses rdt $3\mathrm{.}0$ as its transport layer protocol. As the stop$-$and$-$wait protocol has very low channel utilization, the designers of this application let the receiver keep sending back a number of alternating ACK $0$ and ACK$1$ even if the corresponding data have not arrived at the receiver. Would this application design increase the channel utilization and what if any are potential problems with this approach?

No$,$ the channel utilization will not increase, and no potential problems.

Yes. Causes the sender to send a number of pipelined data into the channel. One potential problem: If data segments are lost in the channel, then the sender of rdt $3\mathrm{.}0$ won't re$-$send those segments, unless there are some additional mechanism in the application to recover from loss.