The Unified Modeling Language used in software development supports two kinds of design models: structural models that show object classes and their relationships and dynamic models that show the interactions between and among objects and their environment. For each of the models listed below, indicate whether it is primarily a dynamic or a structural model.

Group of answer choices

Events acted upon by the system

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Aggregation of objects into sub$-$systems

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Object methods that place calls on other objects

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Object generalization hierarchies

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Sub$-$system responsibilities

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