“The sum of any two whole numbers is a whole number.”

This property of whole numbers is referred to as

The correct option is closure property.

Step-by-Step Explanation:

1. Understanding Whole Numbers:
Whole numbers are the set of non-negative integers, which include $0,1,2,3,4,\dots$

2. Defining Closure Property:
A set of numbers is said to be "closed" under an operation if performing that operation on any two numbers in the set always results in another number that belongs to the same set.

In this case, when we add any two whole numbers, say $a$ and $b$, their sum $(a+b)$ is always a whole number.

For example:
$3+5=8$ (where 3, 5, and 8 are all whole numbers)
$0+7=7$ (where 0, 7, and 7 are all whole numbers)

Therefore, the statement "The sum of any two whole numbers is a whole number" describes the closure property of whole numbers under addition.

3. Overview of Other Properties:
• Commutative property: States that changing the order of operands does not change the result, i.e., $a+b=b+a$.
• Associative property: States that changing the grouping of operands does not change the result, i.e., $(a+b)+c=a+(b+c)$.
• Distributive property: Relates addition and multiplication, i.e., $a\times (b+c)=(a\times b)+(a\times c)$.