Agreat circle isselect one: a. any parallel of latitude. b. the shortest distance between two places on the surface of the earth. c. a circle of circumference whose center coincides with the center of earth. d. a correct magnetic compass direction on a flat map.

C. A circle of circumference whose centre coincides with the centre of earth.

Explanation:

Geodetics is the science that tells about the center of spherical circles whose center coincides with that of a complete sphere.  The great circle also known as the Orthodrome is a sphere whose center passes through the central points of a sphere thus all great circles have the same center and circumference as each other.  In pair of antipodal points which is infinitely form many great circles. The prime meridian 0 degree is an example of this greater circle. They are common for navigation and aviation.  Having an equatorial radius of 6378.137 km of dividing the earth into two equal parts of north and south zones.

There is a great difference between the windward and leeward side of a mountain. windward and leeward sides are opposites.