A loss incurred by a corporation a. must be carried back 2 years before being carried for 5 years. O b. can be carried back 5 years and forward 3 years. O c. cannot be used to reduce taxes in other years except with special permission from the IRS. d. can be carried forward indefinitely. e. can be carried back 3 years or forward 10 years, whichever is more advantageous to the firm