吳先生,長期吸菸,最近診斷有COPD,抽血檢查WBC 5,000/\mathrm{mm}^{3},eosinophil 1%,COPD 評估問卷(CAT)分數為25。下列治療何者最適合?
\mathrm{mm}^{3}
umeclidinium
umeclidinium+vilanterol
vilanterol+fluticasone furoate
umeclidinium+vilanterol+fluticasone furoate