Which principle is used by geologists to determine places in the rock record where Erosion has
removed large sequences of strata?

Are you asking about a street map usage  if so here is your answer  a street map for a very limited area could simply be a bit map or a .jpg image.  but a more general map would probably store the streets as vectors.  but you shouldn't assume that there is one way to do it

The answer is c i think