**Core Concept**
Methyl alcohol poisoning, also known as methanol poisoning, occurs when methanol is ingested and metabolized to its toxic metabolites, formic acid and formaldehyde. Ethanol is used as an antidote to prevent the formation of these toxic metabolites.

**Why the Correct Answer is Right**
Ethanol competes with methanol for the enzyme alcohol dehydrogenase (ADH), which is responsible for converting methanol to its toxic metabolites. By occupying the enzyme's active site, ethanol reduces the amount of methanol that is metabolized to formic acid and formaldehyde, thereby preventing the toxic effects of methanol poisoning. This is known as competitive inhibition.

**Why Each Wrong Option is Incorrect**
**Option A:** Ethanol increases the production of formic acid by increasing the activity of ADH. (This is incorrect because ethanol actually decreases the activity of ADH by competing with methanol for the enzyme's active site.)

**Option B:** Ethanol is converted to formic acid by the enzyme ADH. (This is incorrect because ethanol is not converted to formic acid by ADH; instead, it competes with methanol for the enzyme's active site.)

**Option C:** Ethanol is an agonist at the GABA receptor and increases the activity of GABA. (This is incorrect because the question is asking about the mechanism of action of ethanol in the context of methanol poisoning, not its effects on the GABA receptor.)

**Clinical Pearl / High-Yield Fact**
To remember the mechanism of action of ethanol in methanol poisoning, recall that ethanol "soaks up" the enzyme ADH, preventing methanol from being converted to its toxic metabolites.

**Correct Answer: C. Ethanol competes with methanol for the enzyme alcohol dehydrogenase (ADH), reducing the formation of toxic metabolites.**