Question: Edgar Rickard was a confidant of which 31st President of the United States?

Context paragraphs:
Edgar Rickard: Edgar Rickard (January 17, 1874 – January 21, 1951) was a mining engineer and lifelong confidant of U.S. President Herbert Hoover.  He was the son of mining engineer Reuben Rickard, and the brother of Thomas Rickard, a mining engineer and one-time mayor of Berkeley, California.  He was born on January 17, 1874 in Pontgibaud, France.  For many years around the turn of the century, he was the editor of a mining journal in London.

Herbert Hoover: Herbert Clark Hoover (August 10, 1874October 20, 1964) was an American engineer, businessman, and politician who served as the 31st President of the United States from 1929 to 1933 during the Great Depression.  A Republican, as Secretary of Commerce in the 1920s he introduced Progressive Era themes of efficiency in the business community and provided government support for standardization, efficiency and international trade.  As president from 1929 to 1933, his ambitious programs were overwhelmed by the Great Depression, which seemed to get worse every year despite the increasingly large-scale interventions he made in the economy.  He was defeated in a landslide in 1932 by Democrat Franklin D. Roosevelt, and spent the rest of his life as a conservative denouncing big government, liberalism and federal intervention in economic affairs, as Democrats repeatedly used his Depression record to attack conservatism and justify more regulation of the economy.

José Sarney: José Sarney de Araújo Costa (] ; born April 24, 1930 as José Ribamar Ferreira de Araújo Costa) is a Brazilian politician, lawyer, and writer who served as 31st President of Brazil from March 15, 1985 to March 15, 1990.  He is the oldest living former President, and, as of the death of João Figueiredo in 1999, the only living former President not to have been elected by direct vote.

Herbert Hoover High School (Fresno, California): Herbert Hoover High School is a public secondary school in the Fresno Unified School District serving Fresno, California, United States, in northern Fresno County.  It is named for Herbert Hoover, the 31st President of the United States.  Its mascot is the Patriot.

Herbert Hoover National Historic Site: The Herbert Hoover National Historic Site is a unit of the National Park System in West Branch, Iowa, United States.  The buildings and grounds are managed by the National Park Service to commemorate the life of Herbert Hoover, the 31st President of the United States.  The park was established in 1965, shortly after it was named a National Historic Landmark.  It now encompasses 186.8 acre .

Lou Henry Hoover House: The Lou Henry Hoover House or, very rarely, Lou Henry and Herbert Hoover House, located on the campus of Stanford University in Stanford, California, United States, is the former house of Herbert Hoover, 31st President of the United States, and his wife Lou Henry Hoover, who designed it.  It is now the official home of the president of Stanford.

Presidential library: In the United States, the presidential library system is a nationwide network of 15 libraries administered by the Office of Presidential Libraries, which is part of the National Archives and Records Administration (NARA).  These are repositories for preserving and making available the papers, records, collections and other historical materials of every President of the United States since Herbert Hoover (31st President, 1929-1933).  In addition to the library services, museum exhibitions concerning the presidency are displayed.

Electoral history of Herbert Hoover: Electoral history of Herbert Hoover, 31st President of the United States (1929–1933) and 3rd United States Secretary of Commerce (1921–1928).

Presidency of George H. W. Bush: The presidency of George H. W. Bush began at noon EST on January 20, 1989, when George H. W. Bush was inaugurated as 41st President of the United States, and ended on January 20, 1993.  Bush, a Republican, took office after a landslide victory over Democrat nominee Michael Dukakis in the 1988 presidential election.  He was the first sitting vice president to be elected president since Martin Van Buren in 1836.  Later, Bush, the 41st president, and his oldest son, George W. Bush, the country's 43rd (2001–2009), would become only the second father and son pair to become president.  (John Adams and John Quincy Adams were the first.)  Bush was denied a second term in the 1992 presidential election, which was won by Democrat Bill Clinton.

Inauguration of Herbert Hoover: The inauguration of Herbert Hoover as the 31st President of the United States was held on Monday, March 4, 1929, at the east portico of the United States Capitol in Washington, D.C..  The inauguration marked the commencement of the only four-year term of Herbert Hoover as President and of Charles Curtis as Vice President.  Chief Justice and former President William H. Taft administered the presidential oath of office to Hoover.  This was the first time a Presidential inauguration to be recorded by sound newsreels.  It was also the second (and most recent) time that a former president administered the oath of office to a new President.

Supporting paragraphs: Edgar Rickard Herbert Hoover
Answer: Herbert Clark Hoover