Which atomic orbital is spherical in shape?

Q. Which atomic orbital is spherical in shape? (Note: you should know and be able to recognize the shapes of the s orbital, px, py, and pz orbitals, and dxy, dyz, dxz, dx2-y2 and dz2 orbitals.)

A.            2s

B.            3p

C.            3d

D.            4f

Answer: 2s