With current income on the horizontal axis, the slope of the curve Upper C Superscript d Baseline left parenthesis r right parenthesis plus Upper I Superscript d Baseline left parenthesis r right parenthesis plus Upper GCd(r) Id(r) G is equal to the marginal Question content area bottom Part 1 A. benefit from investment. B. propensity to save. C. propensity to consume. D. product of capital. E. product of labour