On October 1, 2016, White Company declared a property dividend payable in the form of marketable equity securities classified as "available for sale" for financial accounting purposes. The marketable equity securities will be distributed to the common stockholders on December 1, 2016. The investment in equity securities originally cost White $510,000 on August 1, 2016. The investment's fair value on various dates is as follows:

The amount credited to Gain on Disposal of Investments resulting from this dividend transaction should be

a. $20,000

b. 0

c. 25,000

d. 30,000