William Howard Taft earned the Republican nomination in 1912.
Option D
Explanation:
"William Howard Taft" was previously a president of "United States" from 1909 to1913 and tenth chief justice of United States and he is the only person to hold both the offices.
He was incumbent republican president who was nominated for the second time through his team in 1912. Though started with Republican Party but he decided split up from the Republican Party and formed party which coasted him the loss of his position while Woodrow Wilson from the Democratic Party won the election and became the president in 1913.