A 70-year-old man with a history of hypertension and stage 3b chronic kidney disease (eGFR 28 mL/min/1.73m²) presents to the emergency department with acute dyspnea and pleuritic chest pain that began 6 hours ago. He denies recent surgery, immobilization, or lower extremity swelling. Vital signs are: blood pressure 138/82 mmHg, heart rate 102 bpm, respiratory rate 22/min, SpO2 92% on room air, and temperature 37.2°C. Physical examination reveals clear lung fields and no signs of deep vein thrombosis. Laboratory studies show troponin I 0.02 ng/mL (normal <0.04), D-dimer 3.5 mcg/mL (elevated), and BNP 250 pg/mL (normal <100). Computed tomography pulmonary angiography (CTPA) demonstrates no pulmonary embolism but incidentally reveals a small 5-mm pericardial effusion without echocardiographic evidence of tamponade physiology, pulsus paradoxus, or hemodynamic instability. Which of the following is the most appropriate next step in management?

1. A)Initiate therapeutic anticoagulation with low-molecular-weight heparin and transition to warfarin based on the elevated D-dimer and pleuritic chest pain
2. B)Obtain transthoracic echocardiography to characterize the pericardial effusion, assess cardiac function, and exclude alternative diagnosesGABARITO
3. C)Discharge the patient home with outpatient cardiology follow-up and reassurance that the pericardial effusion is clinically insignificant
4. D)Perform urgent pericardiocentesis with fluid analysis given the presence of pleuritic symptoms and elevated D-dimer
5. E)Place an inferior vena cava (IVC) filter to prevent paradoxical embolism through a potential patent foramen ovale