Which of the following is not a unit of the equilibrium constant Kp? (where, Δx = number of moles of products number of moles of reactants)

A. (atm)Δx, when Δx is negative

B. (atm)Δx, when Δx is positive

C. Dimensionless, when Δx = 0

D. (atm)Δx2, when Δx > 0

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