Of the following statements about tax credits, which one is correct?

a) They are allowed as a deduction in the calculation of Taxable Income of an individual

b) They reduce a tax payable by the same amount regardless of a taxpayer;s level of income and marginal tax rate

c) They are allowed as a deduction in the calculation of Net Income for tax purposes under ITA 3(d)

d) Thier impact is greater for taxpayers with a higher marginal tax rate.

e) none of the above