Suppose That a Progressive Individual Income Tax Were Suddenly Indexed

Suppose that a progressive individual income tax were suddenly indexed to the rate of inflation. You would expect, in that case, to see

A) the investment multiplier decline with the marginal propensity to consume.
B) monetary policy become less effective in manipulating the level of GDP in the short run.
C) the interest rate become more volatile over the short run in response to weekly uncertainties in the precise specification of the money supply.
D) the IS curve be drawn steeper than before.
E) none of the above.