Loss Carry-Back Is Best Described As

Loss carry-back is best described as:

A) Using a year's capital losses to offset capital gains in past years.
B) Using a year's capital losses to offset capital gains in future years.
C) The taxable difference between adjusted cost of disposal and UCC, when UCC is smaller.
D) Restatement of all prior years' financial statements if material errors are found
E) Restatement of retained earnings if past losses are discovered.