Roland had a taxable estate of $5.5 million when he died this year. (Reference the 2012 tax rate schedule in Exhibit 25-1 and the Unified Credit schedule in Exhibit 25-5 to answer this problem. Omit the "$" sign in your response). Calculate the amount of estate tax due (if any) under the following alternatives. a. Rolands prior taxable gifts consist of a taxable gift of $1 million in 2005. b. Rolands prior taxable gifts consist of a taxable gift of $1.5 million in 2005. c. Rolands prior taxable gifts consist of a taxable gift of $2 million made in 2008 (within three years of his death)