Final answer:
De Klerk promised to lift the ANC ban, release Mandela, and call for a new Constitution when he became president in 1989.
Explanation:
De Klerk promised:
- To lift the ban on the African National Congress (ANC) operating as a political party.
- To release Nelson Mandela after 27 years as a political prisoner.
- To call for a new Constitution and shut down South Africa's nuclear weapons program.
Learn more about South Africa's transition to democracy here:
https://brainly.com/question/8541616
