Which fundamental mathematical property makes the Mercator projection the standard choice for coastal navigational charts published by SHOA?

1. A straight line drawn between two points represents a line of constant compass heading (rhumb line or loxodrómica)
2. A straight line represents the shortest spherical distance (great circle or ortodrómica) between two points
3. Land areas and ocean surfaces preserve true conformal area scale without any geographical distortion
4. Parallels and meridians intersect at variable oblique angles depending on the local latitude