How are event handler functions managed within the DOM?

Event handler functions in the Document Object Model (DOM) can indeed be set and unset, which is a crucial aspect of managing interactivity in web applications. When an event occurs, such as a user clicking a button, the associated event handler function is executed. Developers have the ability to dynamically add these event handler functions to elements during runtime, using methods like addEventListener for attachment. Similarly, they can also remove these handlers using removeEventListener, which allows for greater flexibility in managing events.

This capability allows developers to manage how and when events are processed, which is essential for creating responsive and interactive user interfaces. The process of attaching and detaching event handlers supports a cleaner, more modular approach to code organization, and it helps prevent memory leaks by ensuring that references can be properly cleaned up.

Other options do not reflect the true nature of event handling within the DOM and lack the dynamic control that is characteristic of modern web development practices.