Question: Assuming the `DataService` has been registered in the providers for the application, which answer best describes what happens based on this component's constructor?

1. It is declaring that the `OrderHistoryComponent` will have its own version of a `DataService` and that it should never use any existing instances. The `DataService` would need to be instantiated within the class as a private field for this code to be comp
2. When Angular creates a new instance of the `OrderHistoryComponent`, the injector will provide an instance of a `DataService` class to the component constructor's first argument. The constructor's `dataService` parameter will be used to set a private insta
3. It provides a way to do component testing only; the constructor has no usage in the actual run of the Angular application.
4. It enables the custom element that the component targets to have a custom property named `dataService` that can be used to bind an existing `DataService` instance to.

Answer: The correct answer of the above question is Option B:When Angular creates a new instance of the `OrderHistoryComponent`, the injector will provide an instance of a `DataService` class to the component constructor's first argument. The constructor's `dataService` parameter will be used to set a private insta