The correct answer B. Participant observation
Step-by-step explanation:
In sociology or the study of society, the Symbolic Interactionist Theory is a theoretical perspective that focuses on micro-level interaction and exchange of meaning mainly through the symbols people create. Because of this, in terms of research, this perspective aims at understanding specific individuals rather than large groups and uses qualitative date techniques such as interviews or observation as these allow researches to understand both interaction and symbols in meaning which are the basic elements in this theory. Therefore, from the options provided the technique a symbolic interactionist would use is participant observation.