Identify the fallacy committed in the following argument: 'My opponent cheated on his taxes. He hired an illegal migrant as a nanny. His views on tax reforms simply cannot be trusted.'

The argument is an ad hominem attack.

It rejects the opponent's views on tax reform by citing his personal misdeeds.

Tax-cheating and hiring an illegal nanny bear on character, not on the reforms.

The truth of a position is independent of its holder's conduct.

Attacking the person instead of the claim is the ad hominem fallacy.