Which of the following integrals will find the area of the surface generated by revolving the curve f(x) = 2x√x with 0 ≤ x ≤ 6 about the x-axis?

a) ∫(0 to 6) 2πx√x dx
b) ∫(0 to 6) 2πx√(2x) dx
c) ∫(0 to 6) 2πx²√x dx
d) ∫(0 to 6) πx²√(2x) dx