The Radical Republicans able to push their own plans through the government because the election of 1866 gave them control of both houses of Congress.
Answer: Option B
Explanation:
Radical Republicans never accepted to Lincoln's plan. They thought that Lincoln was being lenient and blocked his moderate approach with the help of Congress. Since they were the congress's minority party. After the assassination of Lincoln, Andrew Johnson took the presidency.
The Radical Republicans didn't even like Johnson since he had views over the society the same as Lincoln did. Meanwhile, the congress was passing the radical legislation more and more. The 1866 election bolstered the vision of Radical Republicans since lot Republicans took seats in the Congress.