Problem: Over several weeks, an RBT fades vocal prompts to teach a client to say "sad" when she sees another person frowning or crying. Today, the RBT notes that a client independently said the word "sad" when she saw her classmate cry from a skinned knee. This is an example of the vocal response "sad" being under the correct . Show Hint A stimulus control B prompt hierarchy C relational frame D visual prompt. Need Assignment Help?