This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urology, Subject name: Surgery
[{'content': 'High inguinal orchidectomy specimen showed teratoma testis with involvement of epididymis; stage is \nSelect and explain. \nA. T1, B. T2, C. T3, D. T4b', 'role': 'user'}, {'content': "Answer: A \nExplanation: T0- No evidence of tumour. Tis- Carcinoma in situ T1- Tumour limited to testis and epididymis. Vascular/ lymphatic invasion not present. Tumor may invade tunica albuginea but not tunica vaginalis. T2- Tumour limited to testis and epididymis with vascular/ lymphatic invasion. Or tumor extends through the tunica albuginea with involvement of tunica vaginalis. T3- Tumour invades to spermatic cord with or without vascular/ lymphatic invasion. T4- Tumour invades to scrotum with or without vascular/ lymphatic invasion. Reference : page 1085 SRB's manual of surgery 5th edition", 'role': 'assistant'}]