Which of the Following Tax Law Rules Creates Incentives for Tax

Which of the following tax law rules creates incentives for tax planning?

A) The federal income tax itself is deductible in determining taxable income.
B) Reducing the amount of income tax that is paid decreases a taxpayer's allowable deductions.
C) The federal income tax itself is not allowed as a deduction in determining taxable income.
D) None of these are correct.