Solve the differential equation xy(dy/dx) = 0 with y(0) = 8. Write this as an explicit function and determine the interval of x values where the solution is valid.
A) y(x) = 8, valid for all real x
B) y(x) = 8x, valid for x ≥ 0
C) y(x) = 8/x, valid for x ≠ 0
D) y(x) = 8 + x, valid for all real x