The prostate gland surrounds the $A$. It produces a milky, slightly alkaline solution which forms $B$ volume of the semen. The secretion contains $C$ acid and enzymes (acid phosphatases, amylase, pepsinogen, and prostaglandins). $A$, $B$, and $C$ in the above statement are:

• A
  $A - \text{prostate gland}, B - 35\%, C - \text{carboxylic}$
• B
  $A - \text{penis}, B - 40\%, C - \text{carboxylic}$
• C
  $A - \text{urethra}, B - 25\%, C - \text{citric}$
• D
  $A - \text{ureter}, B - 50\%, C - \text{citric}$