Answer:
A phase-out.
Step-by-step explanation:
This means to stop using something which has reached the end of it's functional lifespan. DVD players became obsolete (because new technologies became available) so it's makers decided to explore new alternatives.
This is called decline (or decay) phase which is when the utility and potential value in producing and selling the product begins to drop. This decline eventually reaches the point of zero (which is when the "phase-out" begins).