When real interest rates fall as a result of an unexpected expansionary monetary policy of government:（）

A. aggregate demand decreases leading to both an increase in current output and higher prices in the short run.

B. aggregate demand increases leading to both an increase in current output and higher prices in the short run.

C. aggregate demand increases leading to both a decrease in current output and higher prices in the short run.

物理学中的许多规律是通过实验发现的，下列说法中符合史实的是（）

A麦克斯韦通过实验首次证明了电磁波的存在

B.牛顿通过理想斜面实验发现了物体的运动不需要力来维持

C.奥斯特通过实验发现了电流的热效应

D.法拉第通过实验发现了电磁感应现象