Final answer:
The statement AC=AC demonstrates the reflexive property of equality, which means any quantity is equal to itself and is a fundamental principle in mathematics.
Step-by-step explanation:
If AC=AC, the reason is the reflexive property of equality. In mathematics, the reflexive property states that any quantity is equal to itself. This property is one of the most basic and fundamental in mathematics, used to establish that an expression or a mathematical entity is identical to itself by definition. It is essential when using equations and comparing quantities within algebra and geometry.
The other options, such as the transitive property, are not applicable here. The transitive property involves three elements where if the first is related to the second and the second is related to the third, then the first is related to the third. The corresponding property typically refers to geometric figures and matching angles or sides, while the associative and commutative properties are specific to operations such as addition and multiplication. The reflexive property, however, simply reflects the inherent equality of a mathematical entity to itself.