The Commutative Property of Addition states that changing the order of the addends does not change the sum. In other words, \( a + b = b + a \).
Among the provided options, the correct demonstration of the Commutative Property of Addition is:
5z9 + 8a = 8a + 5z9
This equation shows that the sum of \( 5z9 \) and \( 8a \) is equal to the sum of \( 8a \) and \( 5z9 \), demonstrating the commutative property.