Final answer:
The 'Principal Meridian' is a north-south line used in the Public Land Survey System in the United States as a reference for surveying land, which answers option c). It is distinct from the Prime Meridian, which is the meridian at 0° longitude in Greenwich, England.
Step-by-step explanation:
The correct answer to the given question is option c) A north-south line designated by the Land Ordinance of 1785 to facilitate the surveying and numbering of townships in the United States. In geography, the term Principal Meridian is used to refer to a meridian that is used for reference in surveying and is part of the Public Land Survey System in the United States. Various principal meridians and their corresponding base lines are used as the starting points for the survey of land in a given area.
A meridian in a geographic context is an imaginary line on Earth that runs from the North Pole to the South Pole and is used to determine longitude. These lines help geographers and cartographers organize locations using the latitude and longitude coordinate system. The most famous meridian is the Prime Meridian, which is located at the Royal Observatory in Greenwich, England, and is designated with a longitude of 0°.