Option C, It restricted the power of Black Codes already in force is the right answer.
The Black codes in the united states were the laws that limited the freedom of African Americans. These black codes were passed by the Southern states in 1865 and 1866. Enacted in July 1868, the 14th Amendment in the constitution of America proposed the Citizenship, the Equal Protection and the Due process under the law. This Amendment was an acknowledgement to the problems related to former slaves following the American Civil War. The Equal Protection clause declared that "a state may not refuse any person within its jurisdiction the equal protection of the laws".
