【单选题】

A、production process has been defined as part of an industrial equipment manufacturing project．The process is intended to produce steel bolts with a length of 20cm．The control limits are 19.955cm and 20.045cm．The measurements made at the end of the process yielded the following results：20.033cm，19.982cm，19.995cm，20.006cm，19.970cm，19.968cm，19.963cm，19.958cm，19.962cm，19.979cm，19.959cm．What should be done

A、The process is tinder contr01．It should not be adjuste

B．

A、special cause should be investigated，the process should be adjuste

C．The control limits should be adjuste

D．The measuring equipment should be recalibrate