A 65-year-old man presents with a sudden, persisting monocular visual loss. There is a history of continual ipsilateral headache for the past 12 month

[Kathryn]

#april2020mccqe1

A 65-year-old man presents with a sudden, persisting monocular visual loss. There is a history of continual ipsilateral headache for the past 12 months. What laboratory test is most relevant to the likely diagnosis?
(A) Urinalysis
(B) Complete blood count
(C) Erythrocyte sedimentation rate
(D) Chest X-ray
(E) Cerebral CT scan