- Semantics pertains to the investigation of meaning within language, excluding non-verbal communication.
- Phonetics focuses on the investigation of speech sounds, distinct from body movements or gestures.
- Kinesics is the study of body movements and gestures as a modality of non-verbal communication, encompassing facial expressions, posture, and mannerisms.
- Linguistics is the scientific pursuit of language, yet it does not concentrate on non-verbal communication.
Step 1: Analysis of Terms. The term that accurately describes the study of non-verbal communication, including gestures, facial expressions, and body movements, is Kinesics.
Final Answer: \[\boxed{\text{The correct answer is (3) Kinesics.}}\]