Marketing led (light-emitting diode) lightbulbs, such as the cree led bulb, have been available for only a few years in low lighting levels (lumens). they are designed to replace incandescent and compact fluorescent lightbulbs, in part because of a federal law that phases out incandescent lightbulbs in favor of more energy-efficient ones. led bulbs are more expensive but will last up to 20 years. in what stage of the product life cycle is this product?