If a new product sells well, new firms will enter the market, ushering a(n) ________ stage.

If a new product sells well, it means it have crossed the introduction and growth rate and reached its maturity rate, where the customers have accepted the product pretty well and its selling is at peak, generating maximum possible profits for the organization, now at this stage if any new firm(with the same product, off course) enters the market with even a slight variation in price (be it low or high) due to the gained advantage of similar products in market, the customer will try it, which will take it to its maturity stage in no time.