Externalities from an Economic Perspective

Externalities  - is a cost or benefit experienced by a third party to a resource transfer. Discuss the following:
a) An externality problem is a problem of incomplete information, since profits fail to accurately report gains and losses to society, True or false? elaborate
b) How can the government intervene to make society better from the effects of externalities?
c) Distinguish between positive and negative externalities and give examples
d) Are federal mandates effective in regulating or correcting  externalities, and are they good for society as a whole. Give examples