Pure Competition guarantees efficiency in the long-run because... [choose two responses] only the technique(s) of production with the lowest ATC will be used. producers always have efficiency as their top priority competition within the industry will increase when economic profits are positive and decreases when economic profits are zero. marginal revenue equals marginal cost at the same level of output where ATC is minimized.A only the technique(s) of production with the lowest ATC will be used.B producers always have efficiency as their top priorityC competition within the industry will increase when economic profits are positive and decreases when economic profits are zero.D marginal revenue equals marginal cost at the same level of output where ATC is minimized. Solution marginal revenue equals marginal cost at the same level of output where ATC is minimized.D marginal revenue equals marginal cost at the same level of output where ATC is minimized..