Which of the following is a symptom of delirium?

Disorientation is a key symptom of delirium, making it the correct choice. Delirium is characterized by an acute change in mental status, and disorientation can manifest as confusion regarding time, place, or person. Individuals experiencing delirium may struggle to recognize where they are or what time it is, highlighting a disturbance in their cognitive function.

In contrast, consistent memory recall and increased focus are not indicative of delirium; in fact, they represent the opposite cognitive states. Similarly, being in a state of awareness does not align with the confusion and fluctuating levels of consciousness typically observed in patients experiencing delirium. This further emphasizes the importance of disorientation as a hallmark symptom of the condition.