The best option to show distance from a central location is:
A. a line cartogram
Line cartograms can effectively illustrate distances and can emphasize the spatial relationships and distances from a central location by distorting the lengths of lines based on certain data criteria. Proportional symbol maps (D) can show quantities but may not represent distance accurately. Choropleth maps (C) and diagrammatic cartograms (B) typically represent statistical data or thematic information rather than physical distance.