Definition: In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.
Input: Question: A patient reporting chest and cervicobrachial pain. Physical examination reveals miosis and unilateral enophthalmos. Chest X-ray shows opacity at the apex and erosion of the first ribs. What is your diagnosis? 
 Options:  <1> Pancoast tumor. <2> Mediastinal tumor. <3> Localized pleural mesothelioma. <4> Bronchioloalveolar tumor. <5> Small cell lung cancer with brain metastases.
