Option 1 -> In perfect competition, Average Revenue (TR/Q) = (P×Q)/Q = P. This is correct.
Option 2 -> The price line is horizontal in perfect competition, showing price remains constant at all output levels for the firm. This is correct.
Option 3 -> In perfect competition, each additional unit sold adds exactly P to total revenue, so MR = P. This is correct.
Option 4 -> Total Revenue = Price × Quantity. Since P is constant, TR is an upward sloping straight line through the origin, NOT horizontal. This is incorrect.
Hence, Option 4 -> In a perfectly competitive market, the firm's total revenue curve is a straight line passing through the origin with a positive slope (upward sloping), not horizontal. Since TR = P × Q and price is constant, as quantity increases, total revenue increases proportionally. A horizontal TR curve would incorrectly suggest that total revenue remains constant regardless of output quantity, which contradicts the basic revenue relationship. -> correct