input: The following are multiple choice questions (with answers) about medical knowledge.   **Question:** A 16-year-old male complains of nasal obstruction and recurrent epistaxis for several months. On CT scan of Nose and Paranasal Sinuses, an enhancing mass is seen in the nasopharynx with minimal extension into sphenoid sinus and no lateral extension. What is the stage of this lesion?   (A) IA   (B) IB   (C) IIA   (D) IIB
output: ['(B) IB <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) IA  (B) IB  (C) IIA  (D) IIB <> possible answers', '  A 16-year-old male complains of nasal obstruction and recurrent epistaxis for several months. On CT scan of Nose and Paranasal Sinuses, an enhancing mass is seen in the nasopharynx with minimal extension into sphenoid sinus and no lateral extension. What is the stage of this lesion? <> context']