If x and y are prime numbers such that x > y > 3, then x^2 − y^2 must be divisible by which one of the following numbers?  Choose the correct choice from the following options.
A) 3
B) 7
C) 5
D) 9
E) 12
If x=6 and y=4, then x^2-y^2=20and 20 is divisible only by 5 from the options, thus it must be correct.   Answer: 5.
<result>C</result>
If x and y are prime numbers such that x > y > 3, then x^2 − y^2 must be divisible by which one of the following numbers?