Apple Launched Its IPhone in 2007, the First Smartphone That

Apple launched its iPhone in 2007, the first smartphone that used a multi-touch user interface. iPhone unit sales then skyrocketed for several years. Recently, growth in smartphone sales have slowed and profits have declined due to fierce competition from Samsung, Motorola, Nokia and others. In which stage of the product life cycle are smartphones like the iPhone?

A) decline stage
B) commercialization stage
C) growth stage
D) accelerated development stage
E) introduction stage