A Delivery Company Defines a "Defect" as a Package Delivered $\bar{x}$

Multiple Choice

A delivery company defines a "defect" as a package delivered later than the promised delivery time.Management wants to monitor the proportion of such defect packages per week and plans to sample 120 packages every week.The appropriate control chart is a(n) :

A) $\bar{x}$ -chart.
B) R-chart.
C) p-chart.
D) np-chart.