Concept:International economic pressure, in the form of organised consumer boycotts and sanctions, made apartheid too costly for the South African government to maintain.
Explanation:The Anti-Apartheid Boycott was a worldwide movement supported by the United Nations and many foreign governments.
It called on nations, companies, and ordinary people to refuse to purchase South African products or invest in its economy.
This campaign included trade embargoes, oil sanctions, and the withdrawal of foreign businesses from South Africa.
Sports and cultural boycotts also isolated the country, preventing South African teams and artists from participating internationally.
The economic damage from these boycotts weakened the apartheid regime and increased pressure on the government to negotiate.
Combined with internal resistance led by groups such as the African National Congress, the boycotts forced the government to release political prisoners and begin talks.
This process ultimately led to democratic elections in 1994, with Nelson Mandela becoming president.
The other options, such as the Boston Tea Party and Montgomery Bus Boycott, relate to American history and are not connected to South Africa.
Answer:The Anti-Apartheid Boycott.