This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Uterus, Subject name: Pathology
On routine examination, it is discovered that a 35-year-old woman had been exposed in-utero to Diethylstilbestrol (DES) administered to her mother, who had had a history of recurrent spontaneous aboion. This history suggests that the patient might be at increased risk of which of the following? 
Select and explain. 
A. Adenomyosis, B. Clear cell adenocarcinoma, C. Lichen sclerosus, D. Squamous cell carcinoma
B: Clear cell adenocarcinoma
Answer: B: Clear cell adenocarcinoma 
Explanation: Diethylstilbestrol (DES) is the risk factor for clear cell adenocarcinoma of the vagina and cervix in young women with a history of in utero exposure to DES while their mothers were pregnant.