Final answer:
The word 'sect' in the context of the Middle Colonies refers to a division within a larger religious context, indicating the variety of Christian groups present in the area.
Step-by-step explanation:
The best definition of the word "sect" as used in the selection is C division. In context, a sect refers to a group that is a subset within a larger religious, political, or social organization, often with distinctive beliefs or practices. In the Middle Colonies, the presence of various Christian sects such as Quakers, Mennonites, Lutherans, Dutch Calvinists, and Presbyterians indicates the existence of different divisions within Christianity.
These Christian sects made it challenging for any one group to dominate due to their diverse beliefs and practices, contributing to the religious plurality of the region.