A property of an object is designed to hold data related to that object, similar to how an attribute or characteristic describes something about a real-world entity. In the context of a 'Car' object, properties would represent various descriptive features of a car such as its 'color' or 'model'. The correct answer is 'Car.color', as 'color' is a typical attribute to describe a car and thus a likely property of a 'Car' object. The other options are incorrect because they represent either methods (actions that the object can perform) or incorrectly formatted properties that do not adhere to typical object property naming conventions.