Correct Option: B. France Detailed Explanation: The atomic bomb tests conducted in the Sahara Desert, particularly by France in the 1960s, had significant geopolitical implications, especially for African nations, including Nigeria. Here’s a step-by-step breakdown of why the correct answer is France:

1. Historical Context:
2. After World War II, France began conducting nuclear tests in the Sahara Desert, primarily in Algeria, which was then a French colony. These tests started in 1960 and continued into the 1960s and 1970s.
3. The tests were part of France's efforts to establish itself as a nuclear power and were conducted without much regard for the environmental and health impacts on surrounding countries.
4. Impact on Nigeria:
5. Nigeria, which gained independence from Britain in 1960, was concerned about the implications of nuclear testing in close proximity to its borders. The tests raised fears about radiation exposure and environmental degradation.
6. The Nigerian government, along with other African nations, viewed these tests as a threat to regional stability and security. The tests were seen as a demonstration of colonial power and disregard for African sovereignty.
7. Diplomatic Relations:
8. In response to the nuclear tests, Nigeria severed diplomatic relations with France in 1961. This action was a strong statement against France's nuclear policy and its implications for African nations.
9. The severing of relations was part of a broader movement among African nations to assert their independence and challenge the remnants of colonialism.
10. Broader Implications:
11. The incident highlighted the tensions between former colonial powers and newly independent African states. It also underscored the growing awareness and activism regarding nuclear disarmament and environmental issues in the region.

Why Other Options Are Incorrect:

• A. The United States:
• While the U.S. was involved in nuclear testing during the Cold War, it was not directly responsible for the tests in the Sahara. The U.S. had a different relationship with Nigeria, especially during the Cold War, and did not face the same level of backlash from Nigeria regarding nuclear testing.
• C. Germany:
• Germany was not involved in nuclear testing in the Sahara. After World War II, Germany was focused on rebuilding and was not a nuclear power until much later. Therefore, it did not have a direct impact on Nigeria's diplomatic relations concerning nuclear tests.
• D. Canada:
• Canada has never conducted nuclear tests in the Sahara or had a significant role in nuclear proliferation in Africa. Its relationship with Nigeria has been largely positive, focusing on development and cooperation rather than conflict over nuclear issues.

Revision Summary:

• The atomic bomb tests in the Sahara by France led Nigeria to sever diplomatic relations in 1961.
• Nigeria's concerns were rooted in the environmental and health risks posed by the tests.
• The incident reflects broader themes of post-colonialism and the assertion of African sovereignty.
• Other options (U.S., Germany, Canada) are incorrect as they were not involved in the Sahara nuclear tests or had different diplomatic relations with Nigeria.