State the name of the property illustrated. \[ 1+(3+7)=(1+3)+7 \] Choose the correct answer below. Commutative Property of Addition Distributive Property Associative Property of Addition Both Associative and Commutative Properties of Addition

Step 1 ：The given equation is showing that the grouping of the numbers does not change the result of the addition. This is not about the order of the numbers (which would be the Commutative Property) or about distributing multiplication over addition (which would be the Distributive Property). Therefore, this is illustrating the Associative Property of Addition.

Step 2 ：Final Answer: The property illustrated is the \(\boxed{\text{Associative Property of Addition}}\).