((a)) ** General rule** For purposes of determining the inclusion ratio, every individual shall be allowed a GST exemption amount which may be allocated by such individual (or his executor) to any property with respect to which such individual is the transferor.

((b)) ** Allocations irrevocable** Any allocation under subsection (a), once made, shall be irrevocable.

((c)) ** GST exemption amount** For purposes of subsection (a), the GST exemption amount for any calendar year shall be equal to the basic exclusion amount under section 2010(c) for such calendar year.