Which of the following questions could be answered with some kind of distribution map?

You  forgot the options, but I can give you some examples, maybe this will help:

A distribution map will show you where and how much  of a certain thing is happening. for example: 

the percentage of literate or illiterate people in the different places

some characteristics, for example the average age, or average income  for people in a certain area - here you would give a different colour for the different age or income groups. 

Ibelieve the answer is c. map projections.hope my answer has you : )