What were the effects of the Ostend Manifesto and the caning of Charles Sumner?
A. The South agreed that the secrecy of the manifesto and beating of a senator were both wrong.
B. The South gained more land in Cuba to expand slavery and silenced a northern senator.
C. Northerners were outraged that the South had used such methods in support of slavery.
D. Northerners were outraged that the South had invaded Cuba and killed a U.S. senator.