Final answer:
Group B would argue that global sourcing adversely affects national competitiveness due to job losses and economic insecurity, as well as dependencies on imported goods that could threaten national security.
Step-by-step explanation:
The proposition that would most likely be presented by Group B, arguing against global sourcing, is A) Global sourcing adversely affects national competitiveness. This group would argue that global sourcing can lead to job losses in the home country as production shifts to countries with cheaper labor and less environmental regulation, resulting in rising levels of inequality and lower economic security. They may also highlight the potential threat to national security when a country becomes too dependent on key imported products, such as oil. The debate around global sourcing encompasses various economic, environmental, and social concerns, including the protection of national interests and the potential evasion of environmental protection laws by multinational corporations looking for less stringent regulations.