Final answer:
The fallacy in this statement is ad hominem, where the person making the argument is attacked rather than the argument itself.
Step-by-step explanation:
The fallacy in this statement is known as ad hominem. Ad hominem is a Latin term that means 'against the person.' It is a logical fallacy where someone attacks the person making an argument or the person's characteristics, rather than addressing the actual argument being made. In this case, the person is dismissing the argument for lowering the drinking age by pointing out that the person owns a liquor store, implying bias or self-interest.