In a work center, Machine A has a $20-$minute set$-$up time per batch and a $2-$minute per unit run time.Machine B performs the identical function but has a set$-$up time of $30$ minutes and a $1-$minute run time per unit. The work center makes products in batches ranging from $1$ unit to $100$ units. Assuming capacity is not a limitation on either Machine, in order to minimize the total processing time, on which batches should Machine B be used? Batches of more than $5$ units should run on Machine B$.$ Batches can be run on either machines since they all have the same break$-$even points Batches of more than $10$ units should be run on Machine B$.$ All batches should be run on Machine B since it has the shortest run time per unit Batches with up to $20$ units should be run on Machine B$.$