Which of the Following Tax Law Rules Create Incentives for Tax

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

A) The Federal income tax itself is deductible in determining taxable income.
B) Reducing the amount of income taxes that are 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 the above.