Daleroes, a luxury leather footwear brand, launches Kidsnow, a new range of party footwear for kids. The company heavily invests in advertising campaigns with the tagline "Kids can't stop partying" for promoting the new product line. Despite these efforts, Kidsnow experiences slow sales with negative profits due to the heavy investment in the new product line. In the context of the product life cycle, Kidsnow is in its $\_\_\_\_\_.$

maturity stage

growth stage

decline stage

introductory stage