Two phases α and β are in thermodynamic equilibrium. If x and y are the only components present in the phase α and β and μ^j_i represents the chemical potential of component i in phase j, then the condition for equilibrium is

A. μ^α_x = μ^β_y and μ^β_x = μ^α_y

B. μ^x_β = μ^y_α and μ^x_α = μ^y_β

C. μ^α_x = μ^β_y and μ^α_x = μ^β_y

D. μ^α_x = μ^α_y and μ^β_x = μ^β_y

Answer: Option C