$($a$)$ List all strong $($nonweak $)$ entity types in the ER diagram

$($b$)$ Is there a weak entity type? If so$,$ give its name, its partial key, and its identifying relationship $)$

C$.$ For EMPLOYEE entity, which attribute is composite? Which attribute$($s$)$ is the key? What constraints does the $($min$,$ max$)$ notation on participating entity type in the WORS$\_$FOR relationship specify?

$($d$)$For DEPARTMENT entity, which attribute is multi$-$valued? Which attribute$($s$)$ is the key?