Which of the following is an example of nonverbal communication?

Nonverbal communication refers to the ways in which people convey messages without using spoken or written words. Body language, as mentioned in the correct answer, encompasses a wide range of nonverbal cues, including facial expressions, gestures, posture, and eye contact. These cues can express emotions and intentions and are often perceived as more genuine than verbal communication.

In contrast, speaking loudly and writing notes both rely on verbal communication methods—one uses loudness to convey importance or urgency while the other utilizes written words to communicate ideas or information. Additionally, making phone calls involves spoken language, and even though it may include tone and inflection, it is fundamentally a verbal communication method. Therefore, body language clearly stands out as the example of nonverbal communication among the provided options.