Which is a limitation of two-dimensional representations of earth?
a. the cardinal directions are labeled inaccurately.
b. the distance between two objects may be distorted.
c. they do not include lines of latitude.
d. they do not include lines of longitude.

B. The distance between two objects may be distorted

Explanation:

Our planet, the Earth, has elliptical shape. It is roughly a rounded space objects, being slightly wider on its Equator, making it having more elliptical than true round shape.

This means that Earth can be represented in the most accurate manner if it is in its original shape, just being scaled down of course so that it can be practical for usage.

In practice though, the map projections are not depicting the Earth in a three dimensional manner, but instead they depict it in two dimensions. Representing a three dimensional body in two dimensions usually brings in mistakes in the representations, and this can easily be seen in the map projections. Pretty much all map projection have certain distortions, and that usually happens around the higher latitudes, where the objects are represented much larger than what they are, also making wrong representations between the distances between the objects.