Final answer:
A section of rectangular survey system is of 640 acres. This system was a part of the Land Ordinance of 1785 to organize land sales in the Northwest Territory. The correct option is B.
Step-by-step explanation:
A section in the rectangular survey system contains 640 acres per section. This survey system was implemented as part of the Land Ordinance of 1785, which was one of the long-lasting pieces of legislation that addressed the Northwest Territory.
A township was designed to be six miles square, which equates to 36 square miles. Each township was subdivided into 36 sections, and each section was one square mile or 640 acres. This allowed for an organized sale and division of land for settlers and speculators.
Hence, Option B is correct.