To identify the current UN Secretary General as of April 11, 2025:
1. Antonio Guterres has been the Secretary General of the United Nations since January 1, 2017, following his re-election for a second term ending in 2026.
2. The other individuals (Csaba Korosi, Ban Ki-Moon, Kofi Annan) served in previous terms or are not current holders.
3. This reflects the latest information available.
Therefore, the correct answer is (4) Antonio Guterres.