The Morphological Projectile Point Types Defined at Gatecliff Became Temporal

The morphological projectile point types defined at Gatecliff became temporal types when:

A) surface projectile point finds corresponded to point types found in stratified deposits.
B) a series of radiocarbon dates determined the geological sequence at Gatecliff, and time ranges could then be assigned to the projectile point types.
C) dendrochronological dating assigned exact years to projectile point types.
D) thermoluminescence dated the stratified deposits in which the different projectile points were discovered.