Given the following equilibrium constants, CdCO₃ Ksp​=1.0×10⁻¹² and Cd(NH₃)₄²⁺ Kf​=1.3×10⁷ determine Kc for the dissolution of CdCO₃ in aqueous ammonia (shown below).

CdCO₃(s) + 4 NH₃(ag) = Cd(NH₃)₄²⁺ (ag) + CO₃⁻ (aq)
a) 1.3×10⁻⁵
b) 8.7×10⁻¹⁰
c) 8.7×10⁻¹²
d) 1.3×10¹⁹
e) 7.7×10⁻²⁰