USMLE (United States Medical Licensing Examination) Step 1 Practice Exam

Decreased FEV1/FVC ratio and expiratory wheezing are characteristic of asthma, which is a chronic respiratory condition caused by inflammation of the airways. This leads to a narrowing of the airways and difficulty breathing, resulting in a decreased FEV1/FVC ratio. Pulmonary infarction, or a blockage in the blood vessels of the lungs, would not present with wheezing. Caplan syndrome, an autoimmune disease affecting the lungs, would not typically present with a decreased FEV1/FVC ratio. Perfusion-limited gas exchange, a condition where the transfer of gases in the lungs is limited, would also not result in expiratory wheezing. Therefore, the most appropriate answer is asthma.