Answer:
B. People are likely to dispute borders when they believe their political concerns are not being heard.
Step-by-step explanation:
Excerpt #1 highlights the importance of U.S. congressional representatives being aware of the interests of their district's borders, suggesting that a failure to represent those interests may result in dissatisfaction and lack of support. This idea is reinforced in Excerpt #2, which emphasizes the distinct cultural differences between Sudan and Southern Sudan, suggesting that a failure to acknowledge these differences and represent the concerns of each group may result in disputes over the border. Therefore, we can infer that people are likely to dispute borders when they feel their political concerns are not being heard.