This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urology, Subject name: Surgery
Which of the following is the most effective intravesical therapy for superficial bladder cancer 
Select and explain. 
A. Mitomycin, B. Adriamycin, C. Thiotepa, D. BCG
D: BCG
Answer: D: BCG 
Explanation: Bacillus Calmette-Guerin (BCG) is the main intravesical immunotherapy for treating superficial bladder cancer.BCG is put directly into the bladder through a catheter. The body's immune system cells are attracted to the bladder and activated by BCG, which in turn affects the bladder cancer cells. Treatment is usually staed a few weeks after a TURBT(trans urethral resection of bladder tumour) and is given once a week for 6 weeks at a dose of 120mg in 150ml of normal saline .Reference : page 1036 SRB's manual of surgery 5th edition