**Core Concept**
CSF rhinorrhea refers to the leakage of cerebrospinal fluid (CSF) through the nose, often due to a traumatic injury or congenital defect. This condition requires prompt management to prevent complications such as meningitis and pneumoccephalus.

**Why the Correct Answer is Right**
Immediate management of CSF rhinorrhea involves stabilizing the patient and controlling the leak. The first step is to perform a thorough examination, including a nasal endoscopy to identify the site of the leak. A high-flow nasal oxygen therapy is then initiated to maintain a patent nasal passage and promote CSF drainage. Additionally, the patient is typically advised to remain upright to reduce the flow of CSF. This approach helps to prevent complications and allows for further evaluation and definitive treatment.

**Why Each Wrong Option is Incorrect**
**Option A:** This option might be incorrect as it does not address the immediate need to control the leak and prevent complications.
**Option B:** This option might be incorrect as it does not take into account the patient's need for close monitoring and further evaluation.
**Option C:** This option might be incorrect as it does not provide a clear plan for managing the CSF leak and preventing complications.

**Clinical Pearl / High-Yield Fact**
In patients with CSF rhinorrhea, it is essential to maintain a high index of suspicion for meningitis and pneumoccephalus, and to initiate antibiotic prophylaxis if the patient is at high risk. Regular follow-up and imaging studies are also crucial to monitor the resolution of the leak and to identify any complications.

**Correct Answer: A. High-flow nasal oxygen therapy and upright positioning.**