Answer:
The correct answer is B. violence from rebels and criminal organizations.
Explanation:
B is correct because for number of years many criminal organizations were created on the soil of Mexico, Columbia, Venezuela and other countries, which had large influence on the political situation in those countries.
A is wrong because not indigenous group have no political power, but are very often even degraded by ruling elites.
C is wrong because in most of the countries they have trade and economical connections, including the partnership in different organizations.
D is wrong, because this region is rich with different resources, including oil, woods, water sources...