What is the purpose of city planning? (2 answers)

a. to fulfill federal government requirements***
b. to correct past mistakes***
c. to create an opportunity for state and local governments to cooperate
d. to gain federal funding for city planning efforts
e. to fulfill requirements for renewable energy

3 answers

I don't see any of those questions answered in this website.

http://www.planetizen.com/node/64109
None of these answers make sense, except, possibly, b. But that's not the primary purpose of zoning.

http://www.wycokck.org/Internetdept.aspx?id=6280&menu_id=1032&banner=15284
Any people know this answers? I have also this question?