In which continent did David Livingstone primarily serve?

David Livingstone primarily served in Africa, where he is renowned for his missionary work and exploration during the 19th century. His efforts in Africa were significant as he aimed to spread Christianity and also sought to explore and map the continent, particularly regions that were less known to Europeans at the time. Livingstone's travels took him through various parts of southern and central Africa, where he encountered diverse cultures and geographical challenges. His dedication to combating the slave trade and promoting commerce further highlighted the critical role he played in African history.

The other continents mentioned in the options do not align with Livingstone's principal services. While he may have traveled through Europe for various reasons, including his education and to raise support for his missions, his impactful legacy and the majority of his work occurred in Africa. Similarly, there are no significant accounts of his service in Asia or South America, reinforcing that Africa is indeed the continent where he made his most profound contributions.