Considering the following scenario, which method would be most appropriate when calculating the margin of error for the population mean?

An economist wants to estimate the mean per capita income (in thousands) in a major city in Virginia. He obtains information from 68 workers in the city and finds the mean to be 11.1 with a population standard deviation known to be 4.7. The population is assumed to be skewed to the right.

A.) Normal z-distribution B.) Student's t-distribution C.) More advanced statistical techniques