Answer: d. prostate gland
Step-by-step explanation:
The penile urethra is the part of the external genitalia in males. It is the part of the male reproductive structure. It is surrounded by the prostrate gland internally. The prostrate gland is the walnut like gland it forms initial segment of the urethra. It is associated with the fluid secretions which produce citric acids and enzymes that controls as well as prevents the coagulation of semen in the vaginal orifice of females.