Radiation Seed Therapy Is a Common Method for Treating Some $\mu$

Radiation seed therapy is a common method for treating some prostate cancers and brain tumors. Cesium-131, which decays by electron capture and gamma ray emission with a half-life of 9.69 days, is a new isotope proposed for such treatment. If a tumor were seeded with 1.00 $\mu$ g of cesium-131 (130.91 g/mol) , what would the initial radioactivity level be? Note: 1 Ci = 3.70 $\times$ 10¹⁰/s.

A) 5.84 mCi
B) 78.3 mCi
C) 103 mCi
D) 254 mCi
E) 39.4 mCi