The factor that most significantly contributed to the lack of stability and freedom in Afghanistan among the options provided is B) the Taliban take over of the country. The Taliban's rise to power in the 1990s and their subsequent rule were marked by severe repression, human rights abuses, and the imposition of strict interpretations of Islamic law, which contributed to the instability and lack of freedom in Afghanistan.
While other factors, such as regional conflicts and historical tensions (like those mentioned in options C and D), have had an impact on the broader geopolitical landscape surrounding Afghanistan, the direct impact of the Taliban's governance was particularly detrimental to the country's stability and the freedoms of its citizens. Option A is not relevant as Afghanistan was never partitioned like British India.