Which of the following is a method of non-verbal communication?

Body language is indeed a fundamental method of non-verbal communication. It encompasses facial expressions, gestures, posture, and eye contact, all of which convey messages and emotions without the use of words. For instance, a smile can indicate friendliness, while crossed arms may suggest defensiveness. Understanding body language is crucial in healthcare settings as it helps caregivers interpret patients' emotions, comfort levels, and reactions, which may not be expressed verbally.

Other choices, while they are forms of communication, rely on verbal or written methods. Speaking clearly involves the use of spoken language, writing notes uses written words to convey information, and making phone calls also relies on verbal communication. Therefore, body language stands out as the unique form of non-verbal communication among the given options.