A study of amount of time it takes for a teacher to cover a specific chapter in a math class shows a normal distribution curve with the mean of 7.5 hours and standard deviation of 1.5 hours. If 16 teachers are randomly selected, find:
A. The probability that their mean time will be between 7 and 8 hours
B. The probability that their mean will be below 7 or above 8 hours
C. The probability that their mean will be below 7 and above 8 hours.