An 80-Year-Old Woman Comes to the Physician Accompanied by Her

An 80-year-old woman comes to the physician accompanied by her daughter, who is concerned because her mother no longer participates in group activities.  The patient has lived in an apartment within an assisted-living facility for 12 months.  She now no longer attends communal movie nights or bingo games, eats all her meals in her apartment, rarely watches her favorite television shows, and does not call her family and friends.  She feels well and has not been depressed or fatigued.  She says that she sometimes "forgets stuff" but is still able to function independently.  She has not fallen in the past year.
The patient has osteoporosis, hypertension, osteoarthritis of her hips and knees, diet-controlled type 2 diabetes mellitus, and cataracts.  Current medications include hydrochlorothiazide, alendronate, and calcium with vitamin D.
Her temperature is 37.0 C (98.6 F) , blood pressure is 150/80 mm Hg, pulse is 84/min, and respirations are 16/min.  BMI is 22 kg/m².  The patient is alert, attentive, pleasant, well-dressed, and well-groomed.  Chest and abdominal examinations are unremarkable.  There is no muscle weakness, her deep-tendon reflexes are normal, and her gait is steady.  She scores 27/30 on a Mini-Mental State Examination.  A geriatric depression scale screening test is negative.
Laboratory results are as follows:

Which of the following is the most appropriate next step in management of this patient?

A) Hearing evaluation
B) Home geriatric assessment
C) Homocysteine and methylmalonic acid levels
D) Neuropsychologic testing
E) Thyroid replacement therapy