Question: Who is the chairman of the federal reserve?
Disambiguated questions and answers: question: Who was the 15th chairperson of the Federal Reserve?
Who was the 14th chairperson of the Federal Reserve?
Who was the 13th chairperson of the Federal Reserve?
answer: Janet Yellen
Ben Bernanke
Alan Greenspan
Natural Questions answer: Janet Yellen (from the Wikipedia article "Chair of the Federal Reserve")