The weights gained by male college students during their freshman year follow a normal distribution with a mean of = 1.2kg and a standard deviation of = 5.6kg. Complete the statement.
a) The probability of gaining more than 10kg is 0.5.
b) The probability of gaining less than 1.2kg is 0.5.
c) The probability of gaining between 1.2kg and 5.6kg is 0.68.
d) The probability of gaining less than 7kg is 0.8413.