Provide an appropriate response. A radio station claims that the amount of advertising per hour of broadcast time has an average of 12 minutes and a standard deviation equal to $1.2$ 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 15 minutes. Calculate the z-score for this amount of advertising time. Select one: A. $z=1.15$ B. $z=2.50$ C. $z=-1.15$ D. $z=-2.50$ SP.VS. 719