BE$-4\mathrm{.}9$: Pine and Danner is an architectural firm that is contemplating the implementation of activity$-$based costing. The following activities are performed daily by staff architects. Classify these activities as value$-$added or non$$value$-$added: $($a$)$ designing and drafting, $3$ hours; $($b$)$ staff meetings, $1$ hour; $($c$)$ on$-$site supervision, $2$ hours; $($d$)$ lunch, $1$ hour; $($e$)$ consultation with client on specifications, $1\mathrm{.}5$ hours; and $($f$)$ entertaining a prospective client for dinner, $2$ hours.