Many Ghanaians have complained about the privileges given to our Members of Parliament and elected politicians. Before $2023,$ they were not even paying road tolls while trotro drivers and even okada riders were paying $50$ pesewas per trip on the Tema motorway. The NPP government decided to get rid of the road tolls to ensure the free flow of traffic but rather introduced E$-$levy which led to an outcry by Ghanaians. The Tema motorway has been commissioned by the NPP government to be expanded from two lanes on each side to five lanes on each side respectively. While this is laudable, others fear this project may take more than necessary creating additional traffic commuting on the road. The cost of traveling on it may increase or decrease during construction depending on where you stand as a foot soldier in Ghana. As a student of Public Finance, examine the following concepts:

a$)$ What are public and private goods?

b$)$ What are the characteristics of public and private $($excludable goods$)?$

c$)$ Are there externalities associated with the road construction on the Tema motorway?

d$)$ Explain three policies that can be used to correct negative externalities.