Given the Following Equilibrium Constants,
K_a (HSO₄^-) = 1 $\rightleftharpoons$

Given the following equilibrium constants,
K_a (HSO₄^-) = 1.2 × 10^-2
K_b (CH₃CO₂^-) = 5.6 × 10^-10
K_w = 1.00 × 10^-14
determine the equilibrium constant for the reaction below at 25 °C.
HSO₄^-(aq) + CH₃CO₂^-(aq) $\rightleftharpoons$ SO₄^2-(aq) + CH₃CO₂H(aq)

A) 6.7 × 10^-12
B) 2.1 × 10^-7
C) 1.5 × 10^-3
D) 6.7 × 10²
E) 2.1 × 10⁷