A chart popularly called a great circle chart is the:

• A. Nautical chart
• B. Polyconic chart
• C. Gnomonic chart
• D. Mercator chart

Answer: (C)

When planning routes on a sphere, the shortest path between two points is a great circle. A chart that makes these routes appear as straight lines is the gnomonic chart. This projection maps the Earth's surface from its center onto a plane tangent to the sphere, so every great circle becomes a straight line on the chart. That straight-line property is exactly why navigators use it for plotting long-distance legs, since you can draw a single straight line between endpoints to represent the shortest path.

Other charts don’t share that property. Mercator keeps shapes and compass directions locally but renders great-circle paths as curved lines, which isn’t ideal for shortest-route navigation. Polyconic and general nautical charts serve practical purposes for coastal navigation and other tasks, but they don’t render all great circles as straight lines.