Final answer:
Francis Xavier doubted the potential for Christianity to spread in India, notably due to the incompatibility he perceived between Indian culture and Christian teachings.
Step-by-step explanation:
Francis Xavier believed that Christianity could not take hold in India principally because he found the Indian culture incompatible with Christianity (B). This view was likely influenced by the acknowledgment of the profound depth and resilience of Indian religious traditions and social structures, especially the caste system, which Xavier may have felt was too deeply ingrained for Christianity to easily supplant or integrate within Indian society.
Due to these cultural and religious differences, Xavier doubted the potential for widespread conversion to Christianity in India.