Identify the error in reasoning. 'We should ignore Mr Bello's proposal on the state budget. After all, he failed economics at university.'

The speaker rejects the proposal because of a personal fact about Mr Bello rather than by examining the proposal itself. That is an attack on the person, known as argumentum ad hominem. An appeal to authority would cite an expert to support a claim, a false dilemma presents only two options, and circular reasoning assumes the conclusion in the premise.