When VHS VCRs Were First Introduced, Sales Were Zero

When VHS VCRs were first introduced, sales were zero.As the VCRs started to catch on, sales began to increase more and more rapidly until they peaked.Since the peak, sales have fallen, and in time DVD players or something beyond will make VCRs an unprofitable item to manufacture.This pattern is

A) the research and development cycle.
B) known as development and implementation.
C) the product line planning and exiting cycle.
D) the introduction to decline cycle.
E) the product life cycle.