It is the transitive property. C It's actually a very good example of the transitive property.
The associative property would be (a + b) + c = a + (b + c) If you add a and b together and then add on c, that's the same thing as adding b + c together and then add a to it.
The Commutitive property would be a + b = b + a. Again it does not matter which entry you put into your calculator first.
The symmetry property is a = b or b = a. They are interchangeable. That's not what you are given.