Which of the following is not true of credit scores?
a only the credit bureaus truly know credit scores are calculated.
b having a high score means you are more likely to repay debts.
c the more money you make, the higher your credit score.
d your credit score can impact the car or home you can buy.

The answer is C.  The more money you make, the higher your credit score.
credit is a numerical value to measure your favorability in borrowing activities.
This numerical value is mostly influenced by how good you are in handling your financial responsibilities (whether you're paying debt on time, are you making loan often, etc). so the amount of money you earn has nothing to do in this valuation.