In public speaking, using visual aids effectively primarily aims to:

Using visual aids effectively primarily aims to clarify the speaker's message. Visual aids are tools such as slides, charts, images, or videos that can help reinforce the spoken word by providing a visual representation of key concepts. When a speaker incorporates well-designed visuals, it can make complex information more understandable, helping the audience to grasp the core ideas more easily.

For example, using a graph to illustrate statistical trends can show relationships and changes over time that might be challenging to communicate through words alone. This clarity can enhance the audience's comprehension and retention of the information presented, ultimately contributing to a more effective communication process.

The other options focus on aspects that are not the main purpose of visual aids. For instance, distracting the audience undermines the communication goal rather than supporting it. Enhancing a speaker's authority might be a byproduct of effective visuals but is not their primary function. Lastly, limiting audience engagement contradicts the goal of using visual aids, which is to enhance interaction and involvement by providing a more dynamic and engaging presentation experience.