If a Planetary Ring Had an Inner Diameter of 100,000

Multiple Choice

If a planetary ring had an inner diameter of 100,000 km, an outer diameter of 120,000 km, a thickness of 10 m, and a density of 100 kg/m³, what would be the total mass of material in this ring?

A) 6 *10²⁰ kg
B) 5* 10²³ kg
C) 4 *10¹⁵ kg
D) 2 * 10²¹ kg
E) 3 * 10¹⁸ kg.