Using an unstructured method of inquiry, involve a trained moderator guiding the conversation of a small group of individuals in an intensive discussion about a particular topic.

focus group interviews                                                      

Explanation:

Focus group interview: The term "focus group interviews" is described as one of the tools related to "qualitative market research" in which a specific group of people are being selected and therefore they've been asked for their perspectives or opinions related to a specific topic or scenario. While conducting the focus group interviews, the participants are being provided with an environment in which they get the opportunity to speak up and discuss things among each other.

In the question above, the given statement represents the "focus group interview".

i think it is the third one.