Answer: Option A.
It lowers the head.
Explanation:
The ischial arch is a prominent structure closer to the colliculus seminalis of horse. The ejaculatory duct is lateral to this and correspond to the area of ductus differenc eand vesicular gland opening.
The vesicular glands can be easily catheterized using a small-diammeter, flexible polyethylene catheter or a stylet . The catheter is inserted into the instrument channel of the videoendoscope and serves as a route for direct aspiration of fluid or instillation of pharmacologic solutions for direct treatment.It also helps to guide the scope head into the seminal vesicle .