Informal sector of the economy includes:.
a) government workers
b) unlicensed sellers of homemade goods
c) mass-produced industrial goods
d) the commercial agricultural sector
e) all businesses in the spine of the city

b) unlicensed sellers of homemade goods .

Explanation:

People who are self-employed but without legal registration of a business, who sell things going from home to home or in the streets, the little informal merchants, all of them are people in the informal sector of an economy. These are often unemployed people who can´t find new jobs and have to do this in order to get some income and survive. They aren´t usually registered in social security nor pay taxes.  In some developing countries, the informal sector may be very large.