Confederate Batteries Fired on Fort Sumter When It Was Learned

Confederate batteries fired on Fort Sumter when it was learned that  

A) Lincoln had ordered the fort reinforced with federal troops.
B) Lincoln had ordered supplies sent to the fort.
C) the fort's commander was planning to evacuate his troops secretly from the fort.
D) Lincoln had called for seventy-five thousand militia troops to form a voluntary Union army.
E) southern support for secession was weakening.