Which is correct and most complete? a. Changing 3 to 2 in UCL formulas would cause more false alarms. b. If you do not know exactly how many nonconforming units in a lot, the hypergeometric distribution can be used to calculate the chance of finding X many nonconforming units in a subgroup of size n. c. Absence of assignable causes alone guarantees Xbar is normally distributed. d. All of the above are correct. e. All of the above are correct except parts (a) and (d).