Competitive Market: Demand Vs Price

What will happen to the price and the quantity supplied if the demand for a product increases?.

– The price is horizontal line in competitive market so with increase in demand price should say constant by supplies should increase but this a wrong answer. What am I missing

The demand curve for an individual firm is a horizontal line; the demand curve for the _ overall market _ slopes downward and the supply curve slopes upward. If demand increases, quantity should increase and price should increase.