If the mode of the given data is 45, then find the missing frequencies x and y where the sum of the frequencies is 40. Also, find the mean of the data.
a) x = 25, y = 15, mean = 45
b) x = 20, y = 20, mean = 40
c) x = 30, y = 10, mean = 45
d) x = 15, y = 25, mean = 40