vestibular gland

C. Greater vestibular gland, and immediately above it the urethra.

The term vestibular glands has more than one meaning, both relating to structures found in the female genitalia :

It is a chronic inflammation of the lesser vestibular glands, which lie just outside the hymenal ring.

Greater vestibular glands (female)

Ellen had endured a succession of unsuccessful treatments, including electrocautery, treatment for yeast infection, antibacterial and antiviral medication, removal of the vestibular glands in the vaginal opening, and six treatments with laser surgery followed by two operations that involved cutting away the tissue in the painful area.