Final answer:
The maturity stage of the product life cycle is when the core product achieves a standard in the industry and firms compete on price.
Step-by-step explanation:
The answer to the question is option 2) Maturity. The maturity stage of the product life cycle is characterized by the core product achieving a standard in the industry. During this stage, firms increasingly compete on price rather than product differentiation. This is because the market becomes saturated with competitors offering similar products, leading to price competition as a strategy to attract customers. An example of this stage is the smartphone industry, where various brands offer similar features but differentiate on price to gain a competitive edge.