When interest rates in a given economy are reduced, it causes firms to employ __________ capital goods. In terms of the production function (graphed with labor on the horizontal axis and Real GDP on the vertical axis), this then causes ____________________ .
a. more; the production function to shift upward
b. less; the production function to shift downward
c. more; a movement up along a given production function
d. more; a movement down along a given production function