A 52-year-old woman comes into the emergency department with acute shortness of breath, dizziness and chest pain which startod 4 hours ago. Oxygen saturaton is 88%, on room air. Broath sounds are clear blateraly, chest X-ray is clear and the ECG is identical to the one in her medical record from a yoar ago as pro-operative for radical mastectomy surgery. What should the nurse suspect as most Skoly causing this cient's symptoms? OA STEM 8 Pulmonary embolism. Angina pectoris. Op Acute bronchts.