This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urethra & Penis, Subject name: Surgery
A 65-year-old male patient complains of loss of libido and is found to have a low free and total testosterone level. Treatment is commenced with testosterone supplemental therapy. What is the next step in management after testosterone administration? 
Select and explain. 
A. Check PSA levels, B. Testosterone levels are decreased, C. Decrease in size of benign prostatic tissue lesions occurs, D. Decrease in size of prostatic cancer occurs
A: Check PSA levels
Answer: A: Check PSA levels 
Explanation: PSA levels can increase because both benign and malignant prostatic tissue are sensitive to testosterone (hormonal) therapy. There is increased prostatic growth with elevation of PSA and possible polycythemia.