The Market Values of Dwight's Long-Term Capital Sources Differ from the Book

The market values of Dwight's long-term capital sources differ from the book values because

A) market values are easier to verify than book values.
B) book vales are established at the time securities are issued rather than what the same securities could be sold for if they were issued today.
C) market values are established according to generally accepted accounting principles (GAAP) .
D) All of the above are true.