Final Answer:
Under price-taking behavior, the total revenue curve is a straight line from the origin with a slope equal to the market price. Therefore, the correct option is:
c) a straight line from the origin with slope equal to the market price.
Step-by-step explanation:
Under price-taking behavior, firms in a competitive market accept the prevailing market price as given, meaning they have no influence on it. When plotting the total revenue curve with quantity on the horizontal axis and revenue on the vertical axis, the resulting curve reflects the relationship between the quantity of units sold and the total revenue generated.
In a competitive market, each additional unit sold contributes an amount equal to the market price to the total revenue. As a result, the total revenue curve is a straight line originating from the origin, indicating that revenue increases linearly with the quantity of units sold. The slope of this line represents the market price.
If the total revenue curve were a horizontal line, as in option (b), it would imply that regardless of the quantity sold, total revenue remains constant. However, in a competitive market, firms cannot set the price; they can only sell at the market price. Therefore, the correct depiction is a straight line from the origin, option (c), symbolizing the direct relationship between quantity and total revenue, with the slope equivalent to the market price under price-taking behavior.