Question

which level of government can declare war and regulate trade

Explanation:

In most countries, the power to declare war and regulate trade is a national - level function. National governments have the authority to engage in international relations, which includes declaring war. They also have the power to set policies for international and sometimes domestic trade. Local and state governments usually do not have such far - reaching international powers. "Branches" is not a level of government in this context.

Answer:

A. National