Simplify: (x^1/5y^1/3)^1/4

A) x^1/20y^1/12
B) x^1/20y^12
C) x^20y^12
D) x^5/4y^3/4

The random variable x is the number of occurrences of an event over an interval of ten minutes. it can be assumed that the probability of an occurrence is the same in any two-time periods of an equal length. it is known that the mean number of occurrences in ten minutes is 5.3. the appropriate probability distribution for the random variable