The derivative of the Investment Function with respect to the interest rate tells us: Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. a That the level of investment will decrease as the interest rate increases; ∂I/∂r<0 b That the level of investment will decrease as the interest rate increases; ∂I/∂r>0 c That the level of investment will increase as the interest rate increases; ∂I/∂r<0 d That the level of investment will increase as the interest rate increases; ∂I/∂r>0