In the Equation $I _ { t } / \tilde { Y } _ { t } = \bar { a } _ { i } - \bar { b } \left( R _ { t } - \bar { r } \right)$

In the equation $I _ { t } / \tilde { Y } _ { t } = \bar { a } _ { i } - \bar { b } \left( R _ { t } - \bar { r } \right)$ , if $\bar { b }$
Is close to infinity:

A) investment is extremely sensitive to real interest rate changes
B) investment is somewhat sensitive to changes in the marginal product of capital
C) investment is not very sensitive to real interest rate changes
D) investment is sensitive to tax rate changes
E) the output gap is zero