Building permits/debt to income

Which of the following is most likely to increase after an increase in aggregate real personal income?

  1. A.Equity prices
  2. B.Building permits for new private housing units
  3. C.The ratio of consumer installment debt to income

Why isen’t it B? The right answer is C but shouldn’t it be B? I mean if there is an increase in real personal income so individuals can spend more money, wouldn’t the building permits for new private housing units be increasing? Or should it be interpreted that since the real personal income is increased that debt to income will increase since people will take more loans and spend more?

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