According to the Ricardian equivalence theorem, an increase in government spending without any tax increase will not increase aggregate demand because

a. the private sector is more likely than the public sector to spend any extra income on national defense

b. consumers will consume less and save more to prepare for increased taxes in the future

c. consumers will increase their consumption proportionately more than Keynesian economists believe they will.

d. consumers will save less than they otherwise would have.