Each year, Kiplinger's compiles its list of Best Value Cities.  One of the statistics used in this ranking is the cost-of-living index compiled by the US Department of Labor Bureau of Labor Statistics. The index measures the cost of living in a city relative to the national average of 100. In 2011, Pueblo Colorado had the lowest index (84), while New York City had an index of 118. 

The most appropriate hypothesis test to use for this scenario is:

A) z test for single population proportion 

B) z - test for single sample

C) t - test for single sample

D) t test for single population mean

E) z - test for single population mean