Which of the following scenarios describes a RBT behaving ethically with respect to the use of other therapies?

The scenario in which Mark provides both behavioral intervention as a Registered Behavior Technician (RBT) and speech therapy to his clients while billing for them separately exemplifies ethical behavior. This is because it reflects transparency and an understanding of the distinct nature of each service. By billing separately, Mark ensures that clients are aware of the specific services they are receiving and paying for, maintaining clarity about the scope of practice.

In addition, this approach upholds ethical standards regarding informed consent and financial practices. It allows clients to make informed decisions regarding their treatment options, understanding what they are being charged for each specific therapy. This practice aligns with the ethical guidelines that emphasize the importance of clarity and transparency in billing practices within the field of behavior analysis.