Which of the following is NOT a requirement for transforming a double-faced card?

Transforming a double-faced card requires specific conditions to be met, and recognizing what is NOT required is key. The correct response highlights an important aspect of double-faced cards and their transformation mechanics.

For a double-faced card to transform, it indeed must be a double-faced card, fulfilling the requirement of C. Additionally, there must be a spell or ability that instructs the card to transform, which corresponds with requirement B. When it comes to the requirement regarding the card's location, the transformation typically occurs when the card is on the battlefield, meaning D is also a necessary condition.

The option that is identified as NOT a requirement, therefore, is A. This indicates a misunderstanding of the transformation process, as a double-faced card does not need to be in the graveyard to transform; it can only transform from the battlefield when certain conditions are triggered. Understanding this distinction underscores the mechanics that govern double-faced card transformations and clarifies the overall framework within which double-faced cards operate in games.