Which of the following is considered a technique of non-verbal communication?

Maintaining eye contact is a technique of non-verbal communication because it involves conveying messages without the use of words. It plays a critical role in interpersonal communication, allowing individuals to express confidence, attentiveness, and understanding. Eye contact can signal interest and engagement in a conversation, while lack of it may suggest disinterest or discomfort.

In contrast, using formal speech, writing an email, and giving a presentation predominantly involve verbal or written communication methods. These options rely on the use of language to convey information and are not categorized as non-verbal communication techniques. Non-verbal cues, such as body language, facial expressions, and eye contact, complement verbal messages and can dramatically enhance communication effectiveness.