**Core Concept**
In pediatric trauma, especially after a significant fall, it's crucial to assess for potential head injuries and spinal cord injuries. The child's unresponsiveness and abnormal vital signs necessitate immediate attention to prevent further complications. The cervical spine must be immobilized to avoid exacerbating any potential spinal cord injury.

**Why the Correct Answer is Right**
The child's respiratory rate, pulse, and oxygen saturation are abnormal, indicating potential respiratory and cardiovascular compromise. Providing oxygen by face mask is essential to ensure adequate oxygenation. Immobilizing the cervical spine prevents further injury to the spinal cord. Given the child's unstable condition, transfer to a tertiary center for further evaluation and management is necessary. A doctor should accompany the child during transfer to provide ongoing care and monitoring.

**Why Each Wrong Option is Incorrect**
**Option A:** Observing the child carefully and shifting if necessary is inadequate given the child's unstable condition and potential for further deterioration.

**Option B:** While transferring to a tertiary center is appropriate, immediate transfer without immobilizing the cervical spine and providing oxygen may worsen the child's condition.

**Option D:** Administering mannitol without a diagnosis of increased intracranial pressure (ICP) is inappropriate. Additionally, mannitol is not a substitute for adequate oxygenation and cervical spine immobilization.

**Clinical Pearl / High-Yield Fact**
In pediatric trauma, the "CATCH" mnemonic can help guide initial assessment: C - Circulation, A - Airway, T - Temperature, C - Cervical spine, and H - Head.

**✓ Correct Answer:** C. Start oxygen by face mask, immobilize cervical spine and transfer to a tertiary center accompanied by doctor

✓ Correct Answer: C. Start oxygen by face mask, immobilize cervical spine and transfer to a tertiary center accompanied by doctor