A 19-year-old sexually active female presents with a chief complaint of severe, stabbing lower abdominal pain. She also complains of foul-smelling vaginal discharge and pain with intercourse. On physical examination, she does not have a fever and complains of both abdominal and adnexal pain. Pelvic examination is difficult to perform secondary to pain, but her cervix appears erythematous with mucopurulent discharge coming from the os. When the bed upon which the patient is lying is jarred, she screams in pain. This patient is most likely suffering from an infection that originated in which of the following structures?
c. Fallopian tubes