In which of the following cases would it not be appropriate for a therapist to ask the client(s) to give a testimonial?

a. A former patient who had benefited from anger management therapy. The patient was mandated to attend therapy following his conviction on domestic violence charges.
b. Parents of a child with a learning disorder who was evaluated and diagnosed by a school psychologist. The child benefited greatly from the diagnosis and has showed much improvement in his academic performance.c. A current therapy client who has been through a protocol for obsessive-compulsive disorder. The client has shown immense improvement from not being able to leave her house to holding a steady job. She is now in the maintenance phase of the therapy.
d. All of the above.