Write C# statements to define a method foo, which takes two integers x and y and return a result of x*y.

a. static void foo(int x,int y) {return x*y;}

b. static int foo(int x,int y) {return x*y;}

c. static int foo(int x, y) {return x*y;}

d. static foo int (int x,int y) {return x*y;}