[Solved] In a perfectly competitive market, the process of entry and exit will end when A)price equals minimum marginal cost. B)marginal revenue equals marginal cost. C)economic profits are zero. D)accounting profits are zero. Finely Crystalline: Describes a rock texture that consists of small, closely-packed crystals not easily visible to the naked eye. Calcite: A common mineral form of calcium carbonate, critical in the formation of limestone and marble, and involved in many geological processes. Metamorphosed Fossils: Fossils that have undergone metamorphism, altering their original form and composition due to heat and pressure. Axial Surface: An imaginary surface connecting all the hinge lines of a fold or a series of folds, often perpendicular to the direction of the fold.