Interaction design primarily focuses on which aspect?

Interaction design primarily emphasizes the way users interact with a product, making user interactivity the central focus of its practice. This field is concerned with creating engaging interfaces that facilitate a seamless and intuitive experience for users. It encompasses how a user engages with elements of the design, navigates through a product, and receives feedback throughout that interaction.

By prioritizing user interactivity, interaction design aims to enhance usability, ensuring that each interaction is not only functional but also satisfying and efficient. This involves understanding user needs, behaviors, and contexts, which ultimately leads to designing interactions that resonate with users and foster a positive relationship with the product.

The other choices, while important in their own contexts, do not align with the primary focus of interaction design. Visual presentation pertains to graphic design elements, marketing strategies are about promoting the product, and user acquisition tactics are related to attracting users rather than how they engage with the product itself. Thus, the correct answer encapsulates the essence of what interaction design is all about.