**Core Concept**
The question pertains to the toxic effects of **ethanol** on the human body, specifically the dose that can be fatal. **Alcohol toxicity** is a critical concept in emergency medicine and clinical toxicology. Understanding the lethal dose of alcohol is essential for managing cases of alcohol overdose.

**Why the Correct Answer is Right**
The correct answer is based on the understanding that a **blood alcohol concentration (BAC)** of 0.4% to 0.5% or higher can be lethal due to respiratory depression. This concentration is typically achieved with the consumption of a significant amount of alcohol in a short period, leading to **central nervous system depression**.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it underestimates the lethal dose.
**Option B:** This option might seem plausible but does not accurately reflect the established lethal dose of alcohol.
**Option D:** This option overestimates the lethal dose.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that alcohol toxicity can present with a range of symptoms, from mild impairment to coma and death, depending on the BAC. Prompt recognition and treatment of alcohol overdose are crucial to prevent fatalities.

**Correct Answer:** C. 250-300 ml