Which of the following is not true about the Deceased Spousal Unused Exclusion Amount [Code Sec. 2010{c){4)]?

It applies to the last predeceased spouse of a decedent.

It may be used during life by the surviving spouse (on gift tax returns) as well as at death on the surviving spouse's estate tax return.

It is lost upon the remarriage of the surviving spouse.

Its use must be consented to by the estate of the predeceased spouse.