Consider the Economy's Downward-Sloping Demand for Investment Curve

Consider the economy's downward-sloping demand for investment curve.A decrease in the interest rate causes ________; an improvement in the marginal productivity of capital causes ________.

A) a shift of the curve to the right; a shift of the curve further to the right
B) a movement downward along the curve; a shift of the curve to the left
C) a movement downward along the curve; a shift of the curve to the right
D) a shift of the curve to the left; a movement downward along the curve
E) a movement upward along the curve; a shift of the curve to the right