**Core Concept**
The patient's presentation is likely due to a pulmonary embolism (PE) given the sudden onset of hemoptysis following a procedure. Pulmonary embolism is a clinical emergency that requires prompt diagnosis and treatment.

**Why the Correct Answer is Right**
The procedure performed may have dislodged a pre-existing pulmonary embolus, leading to sudden hemoptysis. The patient's clinical presentation, including the lack of previous symptoms and the timing of the hemoptysis, is consistent with a PE. A chest X-ray (CXR) may show the Westermark sign or Hampton's hump, suggestive of a PE.

**Why Each Wrong Option is Incorrect**
**Option A:** Administration of a bronchodilator would not address the underlying cause of the hemoptysis and may worsen the patient's condition by increasing oxygenation and potentially exacerbating the PE.
**Option B:** Performing a bronchoscopy would be inappropriate given the high suspicion of a PE, and would likely delay the diagnosis and treatment of the underlying condition.
**Option C:** Administering oxygen may not be sufficient to address the patient's hemodynamic instability and may worsen the patient's condition if the PE is causing significant hypoxemia.

**Clinical Pearl / High-Yield Fact**
In patients with suspected PE, a negative D-dimer does not rule out the diagnosis, especially in patients with recent surgery or trauma.

**Correct Answer:** A chest CT angiogram with contrast is the most appropriate next step to confirm the diagnosis of a pulmonary embolism and guide treatment.