In 2009, Jessica placed $250,000 in a savings account listing ownership as follows: "Jessica, Keri, and Jason, joint tenancy with the right of survivorship." Keri and Jason are Jessica's adult children. In 2012, Jason withdrew $50,000 from the account. In 2015, when the account had a balance of $210,000, Jessica predeceases her children.

What are the transfer tax consequences of these transactions in:

a. 2009?

b. 2012?

c. 2015?