When calculating key performance indicators $($KPI$)$ for the comp set, we need to$\_\_\_\_\_\_\_\_\_\_\_\_$before applying the KPI formulas to the values.

a$.$ identify the highest supply, demand, and revenue values of hotels in the comp set

b$.$ identify the lowest supply, demand, and revenue values of hotels in the comp set

c$.$ identify the average values of supply, demand, and revenues of hotels in the comp set

d$.$ combine the supply, demand, and revenue values for each hotel in the comp set