You are computing the control limits for a chart for non$-$conformities $(c$ chart$).$ If applying the formula for the lower control limit results in a negative value, what should be done?

Select one:

a$.$ Set the LCL to $0.$

b$.$ Nothing, a negative value is fine $($as long as it's the lower control limit$).$

c$.$ Multiply by $-1$ to convert to a positive value.

d$.$ Set the UCL to $0.$