Which fallacy justifies an argument by citing its popularity?

The reasoning behind the choice of the Bandwagon Fallacy is rooted in the principle that this fallacy asserts that a proposition is true or acceptable simply because it is popular or widely held. This fallacy utilizes the idea that if many people believe something to be true, then it must be valid, which ignores the necessity of critical evaluation or evidence supporting the claim.

For instance, if someone argues that a product is the best because everyone is buying it, they are relying on the notion that popularity equates to quality or truth, which is not necessarily the case. The appeal to the consensus of the group lacks substantial justification and weakens the argument because the mere number of people who believe something does not provide credible backing.

The other options focus on different logical errors. The Fallacy of Equivocation involves misleading use of a term with multiple meanings, while Appeal to Authority relies on the opinion of a supposed expert, and Appeal to Consequences argues that a belief must be true or false based on the benefits or consequences of accepting it, rather than on its merit or evidence. Therefore, the Bandwagon Fallacy is the most fitting description of the situation presented in the question.