What kind of map would need to show elevation in its legend?

a political map
a road map
a physical map
a resource map

A physical map would need to show elevation in its legend.

The kind of map that would need to show elevation in its legend is a physical map. Physical maps are designed to show geographical features such as mountains, rivers, deserts, and other landforms. Elevation is an important aspect of understanding the geography of an area, so physical maps often include contours or other visual representations of elevation in their legends.