The correct answer is A. methanol.
Methanol is a type of alcohol that is found in many household products, such as windshield washer fluid, paint thinner, and antifreeze. It is also produced when wood is burned. Methanol is a very toxic substance, and even small amounts can be fatal. When methanol is consumed, it is metabolized by the liver to form formaldehyde and formic acid. These substances are very toxic to the central nervous system, and can cause blindness, coma, and death.
Propanol, ethanol, and butanol are also types of alcohol, but they are not as toxic as methanol. Propanol is found in some hand sanitizers and rubbing alcohol. Ethanol is the type of alcohol that is found in alcoholic beverages. Butanol is found in some solvents and fuels. These substances can cause intoxication if consumed in large amounts, but they are not as likely to be fatal as methanol.
In conclusion, the correct answer is A. methanol. Methanol is a very toxic substance that can cause blindness, coma, and death when consumed. Propanol, ethanol, and butanol are also types of alcohol, but they are not as toxic as methanol.