Which one is NOT true?Select one: Select one: a. Even when the sample size is fairly small, the sampling distribution can be assumed to be approximately normal even if the underlying process distribution is not normally distributed. b. The sampling distribution of sample means taken from a process has less variability than the distribution of the process. c. Assignable variation is variation due to a specific cause, such as tool wear. d. A sample statistic that falls outside the control limits suggests that the process mean has changed. e. Control limits are determined based on design specification limits.