Warren Buffett,the Noted Stock Market Investor,and World's Second Richest Man

Warren Buffett,the noted stock market investor,and world's second richest man has noted:

A) his average tax rate is lower than his secretary.
B) his world ranking would increase substantially if taxes were lower $20,000
C) his taxes were so high that he was supporting the government by himself.
D) his wealth was very high because of the low tax rates enjoyed by the rich.