Excerpt adapted from Frederick Douglass: A Biography by National Park Service

In his journey from captive slave to internationally renowned activist, Frederick Douglass has been a source of inspiration and hope for millions. His brilliant words and selfless actions continue to shape the ways in which we think about race, democracy, and the meaning of freedom.
In 1861, the nation erupted into civil war over the issue of slavery. Frederick Douglass worked tirelessly to make sure that emancipation would be one of the war's outcomes. He recruited African-American men to fight in the U. S. Army, including two of his own sons. His sons served in the famous 54th Massachusetts Volunteer Infantry. When black troops protested they were not receiving pay and treatment equal to that of white troops, Douglass went into action. He met with President Abraham Lincoln to lobby on their behalf.
As the Civil War progressed, emancipation seemed forthcoming, and Douglass intensified the fight for equal citizenship. He argued that freedom would be empty if former slaves were not guaranteed the rights and protections of American citizens. A series of postwar amendments sought to make some of these tremendous changes. The 13th Amendment abolished slavery. The 14th Amendment granted national birthright citizenship. The 15th Amendment stated that no one could be denied voting rights on the basis of race, skin color, or previous servitude.
In 1872, Douglass moved his family to Washington, D. C. There were multiple reasons for their move. Douglass had been traveling frequently to the area ever since the Civil War. All three of their sons already lived in the federal district, and the old family home in Rochester had burned down. A widely known public figure by the time of Reconstruction, Douglass started to hold prestigious offices. These included assistant secretary of the Santo Domingo Commission, legislative council member of the D. C. Territorial Government, board member of Howard University, and president of the Freedman's Bank.
After the fall of Reconstruction, Frederick Douglass managed to retain high-ranking federal appointments. He served under five presidents as U. S. Marshal for D. C. (1877-1881), Recorder of Deeds for D. C. (1881-1886), and Minister Resident and Consul General to Haiti (1889-1891). Significantly, he held these positions at a time when violence and fraud severely restricted African-American political activism.
Frederick Douglass died on February 20, 1895, at the age of 77. His relentless struggle for equality against insufferable obstacles makes Douglass a Titan among historical figures.

4
Which sentence from the passage best supports the inference that Douglass had great determination?
A.
When black troops protested they were not receiving pay and treatment equal to that of white troops, Douglass went into action.
B.
The 15th Amendment stated that no one could be denied voting rights on the basis of race, skin color, or previous servitude.
C.
In his journey from captive slave to internationally renowned activist, Frederick Douglass has been a source of inspiration and hope for millions.
D.
He recruited African-American men to fight in the U. S. Army, including two of his own sons.