An 83-Year-Old Community-Dwelling Woman Comes to the Physician for Routine

An 83-year-old community-dwelling woman comes to the physician for routine follow-up.  She has lost approximately 10 lbs (4.5 kg) over the past year and her clothes no longer fit.  She states she has a good appetite and intact senses of both taste and smell.  She has dentures which fit well and no oral complaints.  She lives alone and performs all of her own activities of daily living; however, she no longer drives and needs help with the maintenance of her home.  She denies swallowing difficulties, nausea or vomiting, abdominal pain, or change in bowel habits.  She denies any cough, chest pain, or lower extremity swelling.  Her mood is good 'most of the time.'
Her other medical problems include osteoporosis, type 2 diabetes, osteoarthritis, stress urinary incontinence, and impaired hearing and vision.  Her medications include hydrochlorothiazide, lisinopril, glyburide, ibuprofen, and alendronate.
Her blood pressure is 130/84 mm Hg and pulse is 84/min.  Her BMI is 19.4 kg/m².  She is well-groomed and pleasant.  General physical examination including breast examination is unremarkable.  Her score on a Mini-Mental State Exam is 26/30.  Stool test for occult blood is negative.  Fingerstick blood glucose is 120 mg/dL.  Laboratory results are as follows:

Which of the following is most likely to establish the cause of this patient's weight loss?

A) Chronic infection work-up
B) Detailed social history
C) Geriatric depression scale
D) Malabsorption work-up
E) Occult malignancy screening