You are attempting to complete a health history on an elderly gentleman who is confused. As the patient is a poor historian, you turn to the patient's son who is present at the bedside. The son expresses concern that his father may be developing dementia. Which of these assessments would indicate the patient is experiencing delirium versus dementia?
a. The son expresses his father's attention span has been affected.
b. The confusion has been ongoing and slowly worsening over time.
c. The patient has demonstrated memory impairment for the past few months.
d. The patient was recently prescribed a new anti-histamine.
