$2-$ The medium access control of point$-$to$-$point links is the responsibility of the data link layer. $(T)$

$3-$ One of the disadvantages of the star topology is that it has a single point of failure. $(T)$

$4-$ The network layer in a sender machine interacts with the data link layer in the same machine by exchanging protocol data units $($PDUs$).(F)$

$5-$ The DSL or optical fiber $($eLife$)$ Internet connection from your home to Etisalat can be considered a point$-$to point WAN. $($T$)$

$6-$ If $3$ computers are connected to each other using a bus topology, we can say that there are $3$ point$-$to$-$point links connecting them together. $(f)$

$7-$ In the Internet model, the presentation layer is responsible for machine$-$independent representation of data. $(F)$

$8-$ The data flow between a computer's mouse and the computer central processing unit $($CPU$)$ is simplex. $(T)$

Q$2.$ Choose the correct answer

I$-$ Over a point$-$to$-$point communication link, if a frame is received with an error, the error should be discovered and corrected at

$($a$)$ the data link layer

$($b$)$ the transport Layer

$($c$)$ all of the above

$2-$ If $6$ nodes are connected in a network with a mesh topology, the number of links in the network is

$($a$)15$

$($b$)$ higher than $15$

$($c$)$ less than or equal to $15$