Final answer:
The question related to Ulysses S. Grant's failure to create a successful southern policy during his administration is best answered by the fact that he allowed corruption to develop within his administration.
Step-by-step explanation:
The question seems to be touching on historical events surrounding Ulysses S. Grant and his administration during the Reconstruction era after the American Civil War. The provided options suggest there were certain actions and policies under Grant that led to the failure of developing a successful southern policy. The correct answer to the question, "Which of the following partially explain Ulysses S. Grant's failure to develop a successful southern policy?" is A. He allowed corruption to develop in his administration. Although Grant did not propose to withdraw federal troops from the South and did not oppose Congressional Reconstruction, corruption in his administration undoubtedly weakened his ability to enforce strong and equitable southern policies.