$1)$ In the OSI$/$ISO model, host$-$to$-$host communication is handled by

the following layer:

$($a$)$ link layer $($b$)$ internet layer $($c$)$ transport layer

$($d$)$ application layer

$1\mathrm{.}1$

$($a$)$

$($b$)$

$($c$)$

$($d$)$

In the ISO$/$OSI model, node$-$to$-$node error control is handled by the

following layer:

$($a$)$ application layer $($b$)$ data link layer $($c$)$ network layer

$($d$)$ session layer

$1\mathrm{.}2$

$($a$)$

$($b$)$

$($c$)$

$($d$)$