<s>[INST] context: FIGO staging system for Ca Endometrium Stage Ia Tumor contained to the corpus uteri IA No or less than half myometrial invasion IB Invasion equal to or more than half of the myometrium Stage II Tumor invades the cervical stroma but does not extend beyond the uterusb Stage IIIa Local and /or regional spread of tumorc III A Tumor invades the serosa of the corpus uteri and/or adnexas III B Vaginal and/or parametrial involvement III C Metastases to pelvis and/or para-aoic lymph nodes III C1 Positive pelvic nodes III C2 Positive para-aoic lymph nodes with no without positive pelvic lymph nodes Stage IVa Tumor invades bladder and/or bowel mucosa and/or distant metastases IVA Tumor invasion of bladder and/or bowel mucosa IVB Distant metastases, including intra-abdominal metastases and or inguinal lymph nodes aInclude grades 1,2, or 3 bEndocervical glandular involvement only should be considered as stage I and no longer as stage II. cPositive cytology has to be repoed separately without changing the stage. [/INST] question: Histopathology of staging laparotomy done for carcinoma endometrium reveals more than 50% myometrium invasion with vaginal involvement, parametrial involvement but no pelvic and paraaoic lymph node involvement. What is the Stage of Ca Endometrium ? | options: A: III B B: III A C: III C1 D: III C2 | answer: A </s>