With Respect to the RDTOH Account, Which of the Following

With respect to the RDTOH account, which of the following statements is not correct?

A) The balance is increased by the amount of Part IV tax paid during the taxation year.
B) The balance is reduced by one-third of any dividends paid during the taxation year.
C) The balance is increased by the portion of Part I tax that is designated as refundable.
D) The balance is reduced by any dividend refund for its preceding taxation year.
GRIP And LRIP