Explanation:

Controllers (A)

Controllers handle user interactions and business logic.
JavaScript functions here are used for event handling and calling server-side methods.

Helper (B)

Helpers provide shared utility functions that multiple components can use.
They help organize logic separately from the controller, making code modular.

Renderer (E)

Renderers handle how components are drawn on the UI.

JavaScript in the renderer modifies component rendering behavior before displaying it.

Why Not C or D?

C. Design → Used for defining component properties, not for executing JavaScript.
D. Style → Contains CSS styling, not JavaScript functions.