Final answer:
The test that determines the hair's degree of elasticity is called the Stretch test. This test involves stretching a strand of hair to see how much it can stretch and return to its original length.
Step-by-step explanation:
The test that determines the hair's degree of elasticity is known as the Stretch test. This test involves stretching a strand of hair to see how much it can stretch and return to its original length. Hair that is highly elastic will be able to stretch a significant amount and then bounce back to its original shape.