An SPC chart of a process under study has several recent plot points outside of the lower control limit$.$ The team has taken actions to move the process in this direction, so the out$-$of$-$control condition is a favorable shift. The process improvement team wants to calculate the Cpk in order to assess process capability. What should the team do$?$

A Calculate the Cpk using data prior to the out$-$of$-$control condition.

B Calculate the Cpk using all data since the out$-$of$-$control condition may be favorable.

C Collect $20$ additional data points to confirm the process shift, confirm stability, then calculate Cpk from data collected after the shift.

D Calculate Cp instead of Cpk

E Calculate Ppk instead of Cpk$.$