Provide an Appropriate Response

Multiple Choice

Provide an appropriate response.
-A toxic radioactive substance with a density of 3 milligrams per square centimeter is detected in the ventilating ducts of a nuclear processing building that was used 34 years ago. If the half-life of the
Substance is 10 years, what was the density of the substance when it was deposited 34 years ago?

A) 3.68 mg/cm2
B) 0.28 mg/cm2
C) 79.17 mg/cm2
D) 31.67 mg/cm2