1. Kathleen is married to Paul, and they have two teenage children. Kathleen transfers $1 million of securities to an irrevocable trust, designating a third-party trust company to serve as trustee. The trust provides for discretionary income and principal distributions to Paul for his lifetime. Upon Paul's death, the trust assets will be distributed to Kathleen if she is still living, otherwise to Kathleen's then-living issue per stirpes.

Evaluate Kathleen's estate tax exposure under 2037, stating any assumptions you may find necessary.

2. Same as (1), except Paul can withdraw the trust principal upon written notice delivered to the trustee.

3. Same as (1), except the trust is to be distributed upon Paul's death to Kathleen's then-living issue, per stirpes.

4. Same as (3), except the trust provides that if Paul and Kathleen divorce or legally separate, the trust shall terminate and be paid over to Kathleen.