Answer:
The correct response is Option D. They considered the practice of slavery to be a crime.
Explanation:
The Radical Republicans were a faction of the Republican party who were passionately opposed to slavery and who sought to eradicate it. They are an influence in national politics from 1854 (before the civil war began) to 1877 when Reconstruction ended. They were never formally organized so there was movement in terms of who was allied with the. An example of one of the more prominent Radical Republicans was Pennsylvania Congressman Thaddeus Stevens.