This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Tamoxifen is useful in: 
Select and explain. 
A. Carcinoma prostate, B. Carcinoma ovary, C. Estrogen receptor positive breast carcinoma, D. Seminoma
C: Estrogen receptor positive breast carcinoma
Answer: C: Estrogen receptor positive breast carcinoma 
Explanation: None