Which of the following symptoms may accompany a ruptured ovarian cyst?

Intense pelvic pain is a common symptom associated with a ruptured ovarian cyst. When an ovarian cyst bursts, it can cause significant irritation in the pelvic area, leading to acute pain. This pain is often sudden and severe, and it may be localized to one side of the pelvis depending on which ovary is involved. Patients might also experience other symptoms such as abdominal swelling, nausea, and discomfort, but the intense pelvic pain is a hallmark sign of this condition.

Other symptoms listed, such as flank pain, can occur from other conditions affecting the kidneys or urinary tract, severe headaches are generally unrelated unless they are due to other complications, and chest pain is indicative of a different set of medical issues. Therefore, in the context of a ruptured ovarian cyst, intense pelvic pain is the most directly relevant symptom.