According to the classical dichotomy, when the money supply doubles which of the following double?

According to the classical dichotomy, when the money supply
doubles which of the following double?
a.ÿÿ ÿthe price level and nominal GDP
b.ÿÿ ÿthe price level and real GDP
c.ÿÿ ÿonly real GDP
d.ÿÿ ÿonly the price level