The best response to evaluate why the Belgian Congo was unable to attain peace immediately after gaining independence is:
Mobutu was a poor leader who could not unite the people.
This reflects the internal challenges faced by the newly independent Congo, including political instability, ethnic tensions, and the inability of leaders to effectively govern and unify the diverse population. While other factors may have played a role, Mobutu's leadership was crucial in shaping the post-independence political landscape.