The most accurate 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.
After gaining independence in 1960, the newly formed country faced significant challenges, including political instability, ethnic tensions, and a lack of experienced leadership. Joseph Mobutu's subsequent rise to power did not resolve these issues and instead led to authoritarian rule, further entrenching divisions and contributing to ongoing conflict.