How does a decrease in the price level affect the quantity of real gdp supplied in the long

How does a decrease in the price level affect the quantity of real gdp supplied in the long run?
a. change in the price level do not affect the level of GDP in the long run
b. in the long run, a decrease in the price level increases inflation, which will decrease real GDP
c. in the long run, a decrease in the price level will increase real GDP
d. in the long run, a decrease in the price level decreases inflation which will decrease real GDP