One Major Difference That Is Useful in the Differential Diagnosis

One major difference that is useful in the differential diagnosis of dementia versus delirium is that:

A) Dementia develops slowly and delirium develops quickly
B) The initial symptoms of dementia are more severe than the symptoms of delirium
C) Dementia symptoms are not associated with underlying medical conditions and delirium symptoms usually result from underlying medical conditions
D) Symptoms of delirium involve memory and attention and symptoms of dementia involve only memory