The radii of the internal and external surfaces of a metallic spherical shell are 3 cm and 5 cm. If this is melted and recast into a solid right circular cylinder of height, 10\(2\over3\) cm, then the diameter of the base of the cylinder is ______.
1
7 cm
2
\(7\over2\) cm
3
\(2\over7\) cm
4
\(1\over7\) cm