**Core Concept**
The question is testing the knowledge of intravenous induction agents used in day care surgery, which requires a rapid recovery with minimal side effects. The ideal agent should have a short duration of action, minimal residual effects, and a low incidence of postoperative nausea and vomiting (PONV).

**Why the Correct Answer is Right**
Propofol is the most suitable intravenous induction agent for day care surgery due to its rapid onset and short duration of action (2-3 minutes). It has a low incidence of PONV and does not accumulate in the body, making it ideal for outpatient procedures. Propofol also has a favorable pharmacokinetic profile, allowing for rapid recovery and discharge.

**Why Each Wrong Option is Incorrect**
* **Option A:** Thiopentone has a longer duration of action and may cause more residual effects, making it less suitable for day care surgery.
* **Option B:** Ketamine may cause hallucinations, nightmares, and increased intracranial pressure, which are undesirable in day care surgery patients.
* **Option D:** Etomidate has a long duration of action and may cause adrenal suppression, making it less ideal for day care surgery.

**Clinical Pearl / High-Yield Fact**
Propofol is often used in combination with a benzodiazepine (e.g., midazolam) to reduce the risk of emergence delirium and agitation.

**Correct Answer: C. Propofol**