Here’s a list of all the past Republican Presidents since you didn’t provide the answer choices.
Abraham Lincoln (1861-1865)
Andrew Johnson (1865–1868) (Johnson in 1868 switched to the Democratic Party)
Ulysses S. Grant (1868–1877)
Rutherford B. Hayes (1877–1881)
James A. Garfield (March 4, 1881–September 19, 1881)
Chester A. Arthur (1881–1885)
Benjamin Harrison (1889–1893)
William McKinley (1897–1901)
Theodore Roosevelt (1901–1909)
William Howard Taft (1909–1913)
Warren G. Harding (1921–1923) (died in office of natural causes)
Calvin Coolidge (1923–1929)
Herbert Hoover (1929–1933)
Dwight D. Eisenhower (1953–1961)
Richard Nixon (1969–1974) (resigned in 1974)
Gerald Ford (1974–1977)
Ronald Reagan (1981–1989)
George H. W. Bush (1989–1993)
George W. Bush (2001–2009)
Donald Trump (2017–2021)