Which of the following expressions represents the equilibrium constant (K) for the reaction: aA + bB ⇌ cC + dD?

A. K = [C]^c[D]^d / [A]^a[B]^b
B. K = [A]^a[B]^b / [C]^c[D]^d
C. K = [C]^c / [A]^a
D. K = [D]^d / [B]^b

Answer: K = [C]^c[D]^d / [A]^a[B]^b


Additional Information: The equilibrium constant K is expressed as the ratio of the concentrations of products to reactants, each raised to the power of their coefficients.