Assuming that a firm’s total revenue curve takes the form of a straight line which passes through the origin, we may deduce that

The other options are incorrect because:

• Option B is incorrect because the price of the good or service may be greater than or less than the marginal revenue, depending on the shape of the total revenue curve.
• Option C is incorrect because the total cost curve is the graph of the total cost function, which is the total amount of money that a firm spends on producing its goods or services. The total cost function is always greater than or equal to the marginal cost, which is the additional cost that a firm incurs from producing one more unit of the good or service.
• Option D is incorrect because the elasticity of demand is a measure of how responsive the quantity demanded of a good or service is to changes in the price. The elasticity of demand is equal to one when the demand is unit elastic, which means that a 1% change in the price results in a 1% change in the quantity demanded.