in the context of estate taxation, what is the definition of portability

a. if a trust is valid in the state in which it was signed it is valid in the state in which the decedent died

b. if the first spouse to de does not use their entire applicable credit amount the surviving spouse may be able to use the remainder of the credit

c. portable goods are reported on schedule F

d assets owned by the decedent are included in the gross estate regardless of where they are located