For How Long Is the Chairman of the Board of Governors

For how long is the chairman of the board of governors of the Fed appointed and by whom?

A) Appointed for two years by all the other governors
B) Appointed for two years by the governor of the New York district branch
C) Appointed for two years by the president of the United States
D) Appointed for four years by all the other governors
E) Appointed for four years by the president of the United States