At the U.S. Open Tennis Championship a statistician keeps track of every serve that a player hits during the tournament. The statistician reported that the mean serve speed of a particular player was 96 miles per hour (mph) and the standard deviation of the serve speeds was 10 mph. The lower quartile of serve speeds was reported to be 90 mph. Which of the following interpretations of this information is correct?

a) 75% of the player's serves were hit at speeds greater than 90 mph. b) 25% of the player's serves were hit at 90 mph. c) 75% of the player's serves were hit at speeds less than 90 mph. d) 90 serves travelled faster than the lower quartile in the distribution of serve speeds.