In the Late 1970s (1977 to 1979) the US Economy

In the late 1970s (1977 to 1979) the US economy

A) experienced a shifting of the IS curve to the right because of increased business optimism, tax reductions, and increased government spending.
B) experienced a movement down and to the right along the IS curve.
C) experienced a shifting of the IS curve to the left because of decreased business optimism, tax increases, and decreased government spending.
D) experienced a shifting of the IS curve to the right due to a decrease in interest rates.