10. Let S be the surface parametrized by r(θ, z) = 3sin 2θi + 6sin2θj+zk where 0 ≤ θ ≤ π . Which of the following is equivalent to the surface differential do? (A)dθdz (B)dθdz (C)3dθdz (D)6dθdz (E)12dθdz