Choice "D" is correct. A C corporation's net capital losses are carried back 3 years and forward 5 years; they expire after 5 years. In addition, a C corporation cannot deduct net capital losses from ordinary income.
Choice "b" is incorrect. A C corporation's net capital losses cannot be carried forward indefinitely. They expire after 5 years.
Choices "c" and "a" are incorrect. A C corporation cannot deduct net capital losses from ordinary income.