A Researcher Interviews the Mayors of Nine Canadian Cities

Multiple Choice

A researcher interviews the mayors of nine Canadian cities. She wants to determine whether size of the city (small, medium, or large) is associated with its mayor's assessment of clinic availability (unsuitable, acceptable, excellent) .
-Refer to the scenario. How many unique pairs are there for calculating the measure of association?

A) 3
B) 9
C) 36
D) 81