Regarding Control Charts,changing from Three-Sigma Limits to Two-Sigma Limits

Multiple Choice

Regarding control charts,changing from three-sigma limits to two-sigma limits:

A) increases the probability of concluding nothing has changed,when in fact it has.
B) increases the probability of searching for a cause when none exists.
C) decreases the probability that the process average will change.
D) decreases the probability that defects will be generated by the process.