An 82-Year-Old Man Is Admitted to a Medical-Surgical Unit for Diagnostic

An 82-year-old man is admitted to a medical-surgical unit for diagnostic confirmation and management of suspected delirium. Which statement by the patient's daughter best supports the diagnosis?

A) "Dad has always been so independent. He's lived alone for years since my mom died."
B) "Dad just hasn't seemed to know what he's been doing lately. He has been very forgetful these last few months."
C) "Maybe it's just caused by aging. This usually happens by age 8
D) "The changes in his behavior came on so quickly. I wasn't sure what was happening."