Ans is 'a' ie. testicular biopsy As already explained a testicular biopsy (more specifically a trans-scrotal testicular biopsy) is not done, rather is contraindicated. A suspected scrotal mass is investigated by ultrasonography & on finding a testicular mass, a radical inguinal orchiectomy is done. A trans-scrotal testicular biopsy would breach anatomical barriers and would spread the tumor.