What describes an error in reasoning that makes an argument invalid?

A logical fallacy refers to a flaw in reasoning that undermines the logic of an argument, leading it to become invalid. This term encompasses a range of specific mistakes that can occur when constructing arguments, such as making assumptions without adequate proof or drawing conclusions based on insufficient evidence. Recognizing a logical fallacy is essential in critical thinking, as it helps identify where reasoning breaks down and where a claim may not hold weight.

While the other options listed can represent specific types of logical fallacies—such as false cause, hasty generalization, and circular reasoning—they all fall under the broader category of logical fallacies. However, they refer to particular instances of flawed reasoning rather than describing the general concept. Thus, identifying an argument's core flaw as a logical fallacy appropriately captures the fundamental issue of reasoning error in an argument.