Suppose that in a certain nation, the flat income tax rate of 70 percent falls to 65 percent and as a result the tax base rises from $500 billion to $575 billion. As a result, tax revenues __________, indicating the nation is on the __________ portion of its Laffer curve.

Group of answer choices

A rise; upward-sloping

B rise; downward-sloping

C fall; upward-sloping

D fall; downward-sloping