The Republican Free Labor Ideology

The Republican free labor ideology:

A) convinced northerners that Catholic immigrants posed a more significant threat than the southern slave power.
B) led to the argument by Abraham Lincoln and William Seward that free labor and slave labor were essentially incompatible.
C) owed its origins to Abraham Lincoln's reemergence in the wake of the Kansas-Nebraska Act.
D) accepted southerners' point that slavery protected their liberty, but explained that the economic benefits of free labor would outweigh the damage abolition would do to southern liberty.