Which Situation in the High-Risk Antepartal Unit Requires Immediate Intervention

Which situation in the high-risk antepartal unit requires immediate intervention?

A) A third-trimester patient pregnant with twins who required an appendectomy yesterday is positioned in a supine position.
B) Oxygen is being administered at 2 L via nasal cannula to a patient in her third trimester who underwent an urolithotomy today.
C) Fetal monitoring is being performed on a patient in her third trimester who is scheduled for a cholecystectomy tomorrow.
D) The patient in her third trimester who returned from bowel resection surgery has a nasogastric tube attached to intermittent suction.