Which of the following statements is correct regarding a tax return preparer$$s penalty for aiding and abetting the understatement of a tax liability?

The penalty does not apply if another penalty is assessed with respect to the same action.

The penalty applies to a return preparer who knows about and does not prevent the actions of a subordinate who understates the tax liability.

The taxpayer must have knowledge of the action causing the penalty for the penalty to apply.

The penalty applies to a person who provides only clerical assistance.