I was shocked to see my friend lying at the edge of the road.

Answer: Option D

Side : a position to the left or right of an object, place, or central point.
Bank : the land alongside or sloping down to a river or lake.
Corner : a place or angle where two sides or edges meet.
Border : the edge or boundary of something, or the part near it.
Edge : the outside limit of an object, area, or surface.

Synonym of Edge is Border