Statistical process control charts

Question $20$ options:

a$)$

display the measurements on every item being purchased.

b$)$

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

c$)$

display upper and lower limits for process variables or attributes, and signal when a process is no longer in control.

d$)$

display the measurements on every item being produced.

e$)$

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