Statistical process control charts:

A$.$ display the measurements on every item being produced.

B$.$ display upper and lower limits for process variables or attributes and signal when a process is no longer in contr

C$.$ indicate to the operator the true quality of material leaving the process.

D$.$ indicate to the process operator the average outgoing quality of each lot.

E$.$ are a graphic way of classifying problems by their level of importance, often referred to as the $80-20$ rule.