$2$ points$)$ Match the following:

$($P$)$ SMTP $(1)$ Application Layer

$($Q$)$ OSPF $(2)$ Transport Layer

$($R$)$ TCP $(3)$ Data Link Layer

$($S$)$ PPP $(4)$ Network Layer

$(5)$ Physical Layer

a$.$ P $2,$ Q $1,$ R $3,$ S $5$

b$.$ P $1,$ Q $4,$ R $2,$ S $5$

c$.$ P $1,$ Q $4,$ R $2,$ S $3$

d$.$ P $2,$ Q $4,$ R $1,$ S $3$