Language includes the elements of sounds, words, phrases, and sentences, each of which are related to each other _____.

Language operates as a structured system where various elements such as sounds (phonemes), words (morphemes), phrases, and sentences are interconnected in a systematic manner. This implies that there are specific rules and patterns governing how these elements are combined and used to convey meaning. For example, the syntax of a language dictates how words can be arranged to form grammatically correct sentences, creating meaning that might change with a different arrangement.

The systematic nature of language also encompasses phonology, morphology, and semantics, which all work together cohesively. This systematic relationship allows for the consistent understanding and production of language across different contexts and speakers. In essence, understanding language involves not just recognizing individual words or sounds but also knowing how they are related and can be combined effectively to communicate ideas.

The other choices do not accurately capture the structured and rule-governed nature of language. While elements such as "prototypically" might refer to typical or representative examples in psychological terminology, it does not pertain to the systematic organization of language components. "Heir" and "invariance" also do not apply in this context, as they do not describe the relationship among the various linguistic elements as adequately as "systematically".