<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 22-year-old woman comes to the physician for a routine health maintenance examination. She has no history of serious illness. Pelvic examination shows a pink, 2 x 2-cm, fluctuant swelling at the right posterior vaginal introitus. The swelling is most likely derived from which of the following structures?? A: Vulvar epithelium, B: Paraurethral glands, C: Greater vestibular glands, D: Mesonephric duct remnants, E: Sebaceous glands,  <response>: This is a question about identifying the likely anatomical source of a vaginal swelling in a young woman on routine pelvic exam. The description of a 2x2 cm pink, fluctuant swelling at the posterior vaginal introitus is most consistent with a Bartholins gland cyst. The Bartholins glands greater vestibular glands are located bilaterally at the posterior introitus and drain via ducts that open into the vestibule. They can become obstructed leading to cyst formation. The other options are less likely locations for a cyst of this description in this location. Vulvar epithelium, paraurethral glands, and sebaceous glands would not present as a fluctuant swelling in this location. Mesonephric duct remnants would be an uncommon source for a cyst in a young woman.C: Greater vestibular glands 