A radio station claims that the amount of advertising per hour of broadcast time has an average of 16 minutes and a standard deviation equal to 1.9 minutes. You listen to the radio station for 1 hour, at a randomly selected time, and carefully observe that the amount of advertising time is equal to 6 minutes. Calculate the z-score for this amount of advertising time.

A: z = -0.26

B: z = 5.26

C: z = 0.26

D: z = -5.26