Direct labor is not the best cost driver for a cost related to the purchasing raw materials because the purchasing activity is a$($n$)$ Blank$\_\_\_\_\_\_.$

Multiple choice question.

product$-$sustaining activity and direct labor is a unit$-$level activity

batch activity and direct labor is a unit$-$level activity

cost related to machine hours, not direct labor

unit$-$level activity unrelated to direct labor