In a perfectly competitive market, the marginal revenue curve is?

Horizontal

The correct answer is Option (2) → Horizontal

In a perfectly competitive market, the firm is a price taker — it can sell any quantity of output at the prevailing market price.

• The price (P) remains constant for each additional unit sold.

• Therefore, Average Revenue (AR) = Price and Marginal Revenue (MR) = Price.

Since price does not change with quantity sold, the MR curve is a horizontal straight line at the level of the market price.