The attire a speaker wears would be considered:

The attire a speaker wears is indeed considered nonverbal communication. Nonverbal communication encompasses all forms of communication that do not involve words, and this category includes body language, facial expressions, gestures, and appearance, such as clothing. The way a speaker presents themselves through their attire can significantly impact how the audience perceives their credibility, professionalism, and confidence. Attire communicates messages about the speaker’s identity, social status, and even the seriousness of the occasion, influencing the audience's reception of the speaker’s message.

In contrast, verbal communication pertains specifically to the use of spoken or written words. Visual aids refer to materials like slides, charts, or images that help convey information during a presentation. Parametric communication is not a commonly recognized term in this context and does not apply to the role of attire in a speaker's presentation. Thus, the choice of nonverbal communication accurately reflects how a speaker’s clothing contributes to the overall communication process.