Final answer:
The communication style that involves 'free and easy participation' is most likely the Casual style, which allows for spontaneous interaction and is akin to an informal interview. Clarity and simplicity in writing are key to effective communication.
Step-by-step explanation:
Based on the description given, where there is 'free and easy participation of both speaker and listener', the communication style is most likely C) Casual style. This style of verbal communication is often characterized by a less structured and more spontaneous interaction, similar to an informal interview which has a 'guided' conversation aspect but allows for more control over the exchange by the participant. This is different from a consciousness style or interview-like style, which typically relates to a more formal and controlled setting as might be used in a professional or business environment.
It's important to recognize that while some writers associate good writing style with complexity, clarity and logic should be the primary focus in writing. This ensures that the ideas are conveyed effectively without unnecessary complications. Remember, effective communication in the workplace requires a balance between straightforwardness and diplomacy, depending on the context and the preferred communication style.