All of the Following Undermined the Institution of Slavery in Late-Nineteenth

All of the following undermined the institution of slavery in late-nineteenth century Brazil EXCEPT

A) The inability or refusal of the Brazilian army to suppress the growing runaway slave communities.
B) The Conservative government's refusal to make concessions on the issue.
C) The abolitionists' use of freedom of the press.
D) The coffee planters' transition to immigrant wage labor.