Why did the third estate form the national assembly?

why was the national assembly formed by the third estate?

the estates-general had not been assembled since 1614, and its deputies drew up long lists of grievances and called for sweeping political and social reforms. the third estate, which had the most representatives, declared itself the national assembly and took an oath to force a new constitution on the king.

might be agreeing to participate ethically with other european nations in the slave trade

or notifying other european nations when taking possession   of african territories

yup! you are correct it is b.