Answer :
the national assembly was formed by the third estate because it was the third estate who was treated in a harsh and discriminative manner by the other two estates. so the third estate formed the national assembly
Developed by the delegates of the Third Estate, the National Assembly was a rebellious association. The assembly was formed by the people of the third estate because they wanted to raise their voices for discrimination, to end the system of feudalism and to form their own party for their rights. Although the association was organized without the acquiescence of the monarch, it connected itself with the interests of the King. Hence, all the regulations promulgated by the assembly were subjected to the royal endorsement from the king. In its initial form, this association claimed the prior taxes to be unconstitutional and consequently, encouraged the people to advance a new system of taxation. In order to meet the debts of the ruler, it kept the old tax legislation. However, all this did not give any compensation to the assemblage in order to get rid of the old dilemma of debt and scarcity.