In which case can we be sure that real gdp rises in the short run? a. foreign economies expand and the money supply increasesb. foreign economies expand and the money supply decreasesc. foreign economies contract and the money supply decreasesd. none of the above are correct?

The answer is foreign economies expand and taxes fall.

When economies expanded, the total production that a nation has will increase which will positively contribute to the total GDP.

When taxes fall, the market will attract more investment because it makes the profits goes up, which also will increase the amount of GDP