Natural variations: group of answer choices are variations that are to be identified and investigated. a) are variations that can be traced to a specific cause. b) lead to occasional false findings that processes are out of control. c) are the same as assignable variations. d) play no role in statistical process control.

Lead to occasional false findings that processes are out of control

Explanation:

This happens because natural variations have no way to be predicted and this causes the investigations not to be one hundred per cent accurate and they can "reveal" false information or findings, which only cause the investigation to go out of control and even to cancel the whole operation.

the answer is d.index