A change in which of the following causes a movement along — not a shift in — the IS curve?

Public choice theory predicts that

a) voters are rationally ignorant b) voters are fully informed about the effects of policies c) governments make choices that achieve an efficient provision of public goods d) votes are based on reality, not perceptions

The Taylor rule implies that the Fed should set the federal funds target based on which of the following?

A) the proportionate gap between actual real GDP and a measure of potential real GDP B) the current deviation of the actual inflation rate from the Fed's inflation objective C) an estimated long-run real interest rate D) all of the above