What are the reasons for the development of informal sector?

The informal sector comprises individuals who are self employed or who work for self employed individuals who are not financially registered. Informal workers are not usually taxed. The informal sector developed out of a need for earning money to meet one's need when unable to be gainfully employed in the formal sector and the heavy burden of paying taxes and other regulatory obstacles. 

The answer to this question is b

Answer// dinosaurs emerged during mesozoic era;