Concept:The Great Trek was the mass movement of Dutch-speaking Boers from British-controlled Cape Colony into the South African interior.Explanation:As white communities expanded in South Africa, the area under British colonial authority also grew.This expansion brought more restrictions, especially policies the Boers strongly disliked.Many Dutch-speaking settlers wanted to live outside British rule and maintain their own way of life.From 1836, large groups travelled eastward by wagon into the interior in search of freedom and new land.This movement of the Boer communities is the event known as the Great Trek.Answer:A. The Great Trek.