**Core Concept**
The management of increased intracranial pressure (ICP) involves reducing cerebral edema and cerebral blood volume to prevent further damage. In cases of head injury with rapidly increasing ICP without a visible hematoma, osmotic diuretics are used to decrease ICP.

**Why the Correct Answer is Right**
20% Mannitol is an osmotic diuretic that works by creating an osmotic gradient across the blood-brain barrier, drawing water out of brain cells and reducing cerebral edema. This decreases ICP and cerebral blood volume, thereby reducing the risk of further brain damage. Mannitol is rapidly absorbed and has a short duration of action, making it ideal for acute management of increased ICP.

**Why Each Wrong Option is Incorrect**
**Option A:** Furosemide is a loop diuretic that is not effective in reducing ICP due to its slow onset of action and its ability to increase cerebral blood flow.

**Option B:** Steroids, such as dexamethasone, are used in the management of cerebral edema caused by brain tumors or infections, but they are not effective in reducing ICP in the acute setting of head injury.

**Option D:** Glycine is an inhibitory neurotransmitter that has no role in the management of increased ICP.

**Clinical Pearl / High-Yield Fact**
In the management of increased ICP, the "ABCs" of treatment are: Assess, Bolus, Correct, and Continue. Assess the patient's ICP and clinical status, bolus osmotic diuretics like mannitol, correct any underlying causes of increased ICP, and continue treatment with ongoing monitoring.

**✓ Correct Answer: C. 20% Mannitol**