This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gynaecological Disorders in Obs., Subject name: Gynaecology & Obstetrics
Which one of the following tumors involving the female genital tract has the WORST prognosis? 
Select and explain. 
A. Dysgerminoma in a 35-year-old, B. Uterine choriocarcinoma in a 25-year-old with a recent history of molar pregnancy, C. Granulosa cell tumor in a 40-year-old, D. Serous cystadenocarcinoma of the ovary in a 45-year- old
D: Serous cystadenocarcinoma of the ovary in a 45-year- old
Answer: D: Serous cystadenocarcinoma of the ovary in a 45-year- old 
Explanation: Ans. D. Serous cystadenocarcinoma of the ovary in' a 45-year-oldAround 75% of serous cystadenocarcinoma of the ovary are in an advanced stage at the time of diagnosis.These tumors have a worse prognosis than any of the other tumors listed.