Mammals are adapted to live in the following environments:
a. land
b. air
c. water
d. all of the above

Mammals are adapted to live in D - all of the above. Mammals are, infact, very versatile groups of species which have evolved in a way that also itself enables their versatility. For this reason, mammals have been able to roam the different parts of Earth and thrive in that environment. 

The answer is option a.

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