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

If a planetary ring had an inner diameter of 100,000 km,an outer diameter of 120,000 km,a thickness of 10 meters,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