Concept:The Great Trek involved Dutch-speaking Boers moving inland in southern Africa, where they met strong African kingdoms.Explanation:During the 1830s, the Boers migrated from the Cape Colony to escape British rule.As they moved into the interior, they encountered indigenous groups who resisted their expansion.The most notable clashes were with the Zulu under King Dingane and with the Xhosa on the eastern frontier.These conflicts shaped the history of South Africa during the Great Trek.Answer:B. Zulu and Xhosa.