A 32-year-old woman on oral contraceptives has pleuritic chest pain, HR 115, and SpO2 92%. Wells score is high. CT pulmonary angiography is delayed by 3 hours. What is the BEST immediate step?

1. AGive thrombolysis immediately
2. BDischarge with analgesia
3. CStart anticoagulation while awaiting CT
4. DWait for the CT before any treatment