Why Is the Maximum Alcohol Content of Wine Typically Around

Why is the maximum alcohol content of wine typically around 12%?

A) Because at this point, the alcohol poisons the yeast and the fermentation process that produces the alcohol stops
B) Because the yeast runs out of a carbohydrate source to ferment
C) Because the accumulation of alcohol lowers the temperature enough that fermentation cannot proceed
D) Because the pH is raised during fermentation which denatures the enzymes needed to continue the process