Historically, the Average Time to Service a Customer Complaint Has $\bar{x}$

Multiple Choice

Historically, the average time to service a customer complaint has been 3 days and the standard deviation has been 0.50 day. Management would like to specify the control limits for an $\bar{x}$ chart with a sample size of 10- and 3- sigma limits. The LCL for the chart would be:

A) less than 2.40.
B) greater than 2.40 but less than or equal to 2.45.
C) greater than 2.45 but less than or equal to 2.50.
D) greater than 2.50.