How does "Object#method_missing" combined with "respond_to_missing?" form a complete dynamic method pattern?

A method_missing alone is sufficient; respond_to_missing? is purely decorative and has no effect B method_missing handles the actual dynamic dispatch, while respond_to_missing? should be overridden so that respond_to? correctly reports true for the dynamically handled methods, keeping introspection consistent C respond_to_missing? replaces method_missing entirely in modern Ruby D Both methods are only usable on modules, not classes