Concept:The National Assembly is the law-making arm of the Nigerian government.
Explanation:The National Assembly is a bicameral legislature made up of the Senate and the House of Representatives.
Its primary function is to make laws for the peace, order, and good governance of the federation.
Although it also performs oversight and can confirm certain appointments, its central role is legislation.
Executing laws is the function of the executive arm, while interpreting laws belongs to the judiciary.
Therefore, the main responsibility of the National Assembly is law-making.
Answer:D. Making laws.