Which statement correctly differentiates between an apoenzyme and a holoenzyme?

• A. An apoenzyme is active without its cofactor, while a holoenzyme is inactive with its cofactor.
• B. A holoenzyme is inactive without its cofactor, while an apoenzyme is active with its cofactor.
• C. Both apoenzymes and holoenzymes are active forms of enzymes.
• D. An apoenzyme is inactive without its cofactor, while a holoenzyme is active with its cofactor.

Answer: (D)