Which of the Following Statements About the Time Period Variable

Which of the following statements about the time period variable is false?

A) If Congress replaced the current progressive income tax rates with a proportionate rate applying to all taxpayers, the time period variable would no longer be a factor in tax planning.
B) The time period variable becomes more important as the taxpayer's discount rate for computing NPV increases.
C) Tax planning strategies based on the time period variable must involve at least two different taxable years.
D) Tax planning strategies based on the time period variable reflect the time value of money.