Choice "A" is correct. With regards to a tax shelter, a penalty for understatement of taxpayer liability could apply to a CPA unless it is reasonable to believe that the position would more likely than not be upheld on its merits. This is more stringent than a reasonable basis for the position, a reasonable possibility of success for the position, and substantial authority for the position.Choices "b", "d", and "c" are incorrect per the above explanation.
