pla answer the below quastions in details ASAP

In his book An inquiry into the nature and causes of the wealth of nations (1776), Adam Smith (1776) introduced two basic concepts, which were the principles of taxation, and the invisible hand.

a) Explain Adam Smiths four principles of taxation and state with examples how these principles have been applied in the tax system of Oman.

b) Discuss the concept of the invisible hand as described by Adam Smith.