Concept:The African Union (AU) is mainly challenged by political disagreements among its member states.
Explanation:The AU was created to promote unity, peace, and development in Africa.
Its major challenge is not a lack of natural resources, poor social cohesion, or a weak labour force.
Instead, tensions and political discord among member states often slow down cooperation and joint decision-making.
Such disagreements make it harder for the AU to achieve its objectives.
Thus, the most accurate challenge from the options is political discord among member nations.
Answer:B. tensions and political discord among member states.