If an emissions tax of $500 per unit and the price of a tradeable emissions permit of $500 is established: only firms with newer technology will reduce their pollution to the point where their marginal benefit is $1,000. only firms with older technology will reduce their pollution to the point where their marginal benefit is $1,000. firms will reduce pollution to the point where its marginal benefit is $1,000. firms will reduce pollution to the point where its marginal benefit is $500