Final answer:
The key to successful client relationships is open communication. Genuineness, empathy, and understanding are also critical to building strong relationships with clients, drawing from the principles emphasized by psychologist Carl Rogers.
Step-by-step explanation:
The key to successful client relationships, as indicated in the multiple-choice options, is C) Open communication. The other choices listed, such as ignoring client preferences, lack of empathy, and inflexibility, are typically detrimental to building strong and effective client relationships. Successful client relationships are founded upon mutual understanding, trust, and regular, clear lines of communication.
It's also important to reference the humanistic psychologist Carl Rogers, who emphasized the importance of providing genuineness, empathy, and a non-judgmental environment to clients as critical aspects of therapeutic relationships in psychology. Although this is not directly mentioned in the question's options, these same principles can be applied to client relationships in a business or professional context. They help in understanding the client's needs and building a strong and effective partnership based on those needs.
In this context, 'genuineness' refers to the authenticity and honesty in interactions with clients, while 'empathy' involves understanding and sharing the feelings of others. In contrast, the concepts of structuralism and functionalism are theories in psychology unrelated to the concept of key client relationship factors mentioned in the initial question.