which of the following statements is incorrect with regard to the product life cycle concept? a without regulatory incentives, new products are unlikely to move past the introduction stage b unless the product reaches growth stage, profitability is likely to be elusive c greater control over costs can allow a product category to generate profit even in the decline stage d the stages in the product life cycle may be rigidly defined but the duration of each stage is not e incremental product improvements can extend the duration of the growth and maturity stages