MacDonald Says That "Descartes' Proof That the State of Waking

MacDonald says that "Descartes' proof that the state of waking cannot be distinguished from sleep depends upon these facts: (a) that dreams are remembered, and (b) that what is so remembered resembles an object or combination of objects perceived when awake." But MacDonald argues that the criteria of "real" and "illusory" physical objects which apply to the perceptions of waking life ...

A) cannot be applied to illusions.
B) are identical to those that are applicable to dreams.
C) are artificial, and thus not certain.
D) do not apply to the contents of dreams.