In its year end financial statements, Big Bank Corporation reports marketable debt securities of $554,798 million. The footnotes disclose that these securities have an amortized cost of $558,614 million. Which of the following is true?

Select one: a. There are net unrealized losses of $3,816 million on these securities. b. These are trading securities. c. These are available-for-sale securities. d. Both A and C e. Both B and C