Which one of the following is the most suitable teaching aid to show…

Concept: No flat surface can perfectly represent a sphere -- converting Earth's curved surface into a flat map (a 'map projection') always distorts at least one of: shape, area, distance, or direction, because a sphere cannot be unrolled onto a plane without stretching or tearing it. A globe avoids this problem entirely because it is itself a scaled-down sphere, not a projection -- so it alone preserves continents' true relative size and shape.

Application: The question asks specifically for the aid that shows continents' proportionate size and shape -- exactly the two properties that map projections cannot both preserve. Among the four options, only the globe is a genuine three-dimensional model of Earth; the physical and political maps are both flat projections built for other purposes (terrain relief, and political boundaries, respectively), so neither guarantees true comparative proportions. Hence the globe is the most suitable teaching aid here.

Cross-check/Contrast: Contrast with the distractors: both the physical map and the political map in the options are, like any flat world map, drawn on some map projection -- so whichever projection is used, each inherits that projection's distortion of shape and area. A physical map is optimised to communicate terrain and relief, and a political map is optimised to communicate administrative boundaries, but neither format changes the underlying fact that a flat map cannot avoid this distortion the way a globe (a genuine three-dimensional scaled model) can. Since one option (the globe) does satisfy the requirement, 'none of these' cannot be correct.