Roland had a taxable estate of $15.5 million when he died this year.

Calculate the amount of estate tax due (if any) under the following alternatives

a.Roland's prior taxable gifts consist of a taxable gift of $1 million in 2005.

b.Roland's prior taxable gifts consist of a taxable gift of $1.5 million in 2005.

c.Roland made a $1 million taxable gift in the year prior to his death.