**Core Concept**
Ketamine is an NMDA receptor antagonist used for its anesthetic and analgesic properties. However, it has several contraindications and precautions due to its potential to increase intracranial pressure (ICP) and cause psychomimetic effects.

**Why the Correct Answer is Right**
Ketamine can increase ICP by causing vasodilation and increasing cerebral blood flow. However, in certain conditions, ketamine may be beneficial due to its sympathomimetic effects, which can increase blood pressure and maintain cardiac output. This makes it a useful option in patients with severe head injury or those who are hypotensive. Additionally, ketamine's analgesic properties make it a good choice for patients in pain.

**Why Each Wrong Option is Incorrect**
**Option A:** Glaucoma - Ketamine can increase ICP and worsen glaucoma, making it a contraindication in this condition.

**Option B:** Schizophrenia - Ketamine's psychomimetic effects can exacerbate schizophrenia, making it a contraindication in patients with this condition.

**Option C:** Status asthmaticus - Ketamine's bronchodilatory effects make it a useful option in status asthmaticus, but it's not a contraindication.

**Option D:** Severe hypertension - Ketamine can increase blood pressure, making it a contraindication in patients with severe hypertension.

**Clinical Pearl / High-Yield Fact**
Ketamine's sympathomimetic effects can increase blood pressure and maintain cardiac output, making it a useful option in patients with severe head injury or those who are hypotensive.

**Correct Answer:** C. Status asthmaticus.