A sporting goods store specializes in mountain bikes. Each week, two dozen mountain bikes are randomly selected from the store's warehouse to undergo a performance test. What is the population for the performance test?

A.
The population is all of the mountain bikes in the store's warehouse.
B.
The population is the salespersons at the store.
C.
The population is all of the merchandise sold by the store.
D.
The population is the mountain bikes that are not randomly selected.