In Angular, to create a custom attribute directive, you use the @Directive decorator to define its metadata. This decorator allows you to specify the selector, inputs, outputs, and other properties that determine how the directive behaves when applied to elements in the DOM. The other options, such as @Component, @Attribute, and @Metadata, are not typically used for creating attribute directives.

The ChangeDetectionStrategy.OnPush setting in Angular tells the framework to perform change detection only when the inputs to a component change, rather than after every event. This optimization reduces the frequency of change detection cycles, which can significantly improve performance, especially in complex applications.

To determine if the user has interacted with a particular form control in Angular Reactive Forms, you would check the touched property of the FormControl instance. It becomes true when the user has focused and blurred the form control, indicating interaction. The dirty property indicates if the value has changed.

You can set default headers for all HttpClient requests by using an interceptor. Interceptors allow you to intercept outgoing requests and modify them, including adding default headers, before they are sent.

In Angular, a component controls a patch of the screen called a view. Components are the main way to build and specify elements and logic on the page, making them the primary building block of an Angular application.

In template-driven forms, default values for form controls are typically set programmatically in the component by initializing the corresponding form control variables with the desired default values. While you can assign values directly in the template, this doesn't allow for dynamic default values or interaction with the component logic. The other options mentioned are not common practices for setting default values in template-driven forms.

The map operator in RxJS primarily transforms data emitted by an Observable. It allows you to apply a function to each item emitted by the source Observable and returns a new Observable with the transformed values.

Dynamic components in Angular allow you to create and render components at runtime. This is particularly useful for displaying complex modal dialogs based on user interactions. You can dynamically load the modal component when needed, keeping the main application bundle smaller and improving performance. The other options do not accurately describe the capabilities of dynamic components.

When using Lazy Loading without proper planning, circular dependencies can arise. This occurs when two or more modules depend on each other, causing issues with module resolution and potentially leading to runtime errors. It's essential to structure modules carefully to avoid this problem.

In an HttpInterceptor, you would use the intercept method to catch and handle HTTP errors. This method intercepts outgoing HTTP requests and incoming responses, giving you the opportunity to handle errors and modify requests before they are sent.