What is a price line?

The correct answer is Option 4: All of these

A price line represents the price at which a firm can sell its product in a perfectly competitive market. Since the firm is a price taker, the price remains constant at all levels of output, leading to the following properties:

1️⃣ "The price line shows the relationship between the market price and a firm’s output level." ✅A firm can sell any quantity at the given market price, and the price line reflects this relationship.

2️⃣ "In a perfectly competitive market, it is a horizontal straight line that cuts the y-axis at a height equal to price." ✅ Since price remains constant, the price line is perfectly elastic (horizontal) at the market price.

3️⃣ "The price line depicts the demand curve facing a firm." ✅ In perfect competition, the firm’s demand curve is the same as the price line because buyers can buy any quantity at the given price.This also means the demand curve = AR curve = MR curve in perfect competition.