From the given sentence, extract the phrase (often noun or verb) that carries the given relationship. The generated phrase should be present in the sentence.

Given Relationship: 'be chairman of', Sentence: 'With the appointment of Ben Bernanke to replace Federal Reserve chairman Alan Greenspan , the outlook for the economy appears to be one of higher inflation and rising commodity prices , Aaron Task told " RealMoney " radio show listeners Wednesday .'
chairman