Final answer:
In the Trobriand Islands, the British colonialists replaced local warfare with trade and exchange activities, such as the kula ring.
Step-by-step explanation:
In the Trobriand Islands, the British colonialists substituted trade and exchange activities, such as the kula ring, for local warfare. The Trobriand Islanders engaged in a ceremonial exchange of white shell bracelets and red shell necklaces, which functioned as a means of enhancing social status and reinforcing trade relationships. This exchange system, known as the kula ring, replaced the need for warfare and provided a peaceful way for different island groups to interact.