One of the following is correct regarding Ethemet:

a$)$ Ethemet has broadeast nature which means every sent frame is heard by all destinations. Hence, destination address field is not necessary in the frame header.

b$)$ Ethemet requires source and destination addresses in the frame header to serve the purpose of multiplexing and demultiplexing.

c$)$ Ethemet checksum is calculated for the frame header only.

d$)$ Ethemet is a layer $3$ protocol.

e$)$ None of the above.

The delay that increases as the sixe of the packet increases is:

a$.$ Propagation.

b$.$ Transmission.

c$.$ Queuing:

d$.$ Processing.

e$.$ All of the above

The advantage of Link State $($LS$)$ over Distance Vector $($DV$)$ is:

a$)$ LS messages are usually smaller than DV messages.

b$)$ With LS a computational error at one node does not affect other nodes.

c$)$ With LS computations are performed locally at each node.

d$)$ LS seales better than DV$.$

c$)$ All of the above.

ARP is a soft state protocol. Sof state means:

a$)$ Receiver crash cannot be detected until an ARP request is sent and ARP reply is received.

b$)$ ARP stores state information learned from previous requests.

c$)$ ARP request must be sent after the expination of a time interval of specific length.

d$)$ ARP information is invalid after a time interval of specific length

e$)$ All of the above.