Under the constitution, the principle of "federalism" is the reason that power and responsibility are a. shared by state and national governments b. divided into three branches of government c. limited to what is listed in the amendments d. granted to the states through amendments

A - shared by state and national governments

Under the Constitution, the principle of federalisim is that power is shared between multiple levels (national, state, etc) to allow citiziens to have their voice heard.

do u have any answer choices?

because the vietnam war was fought in an especially brutal and untraditional way