Errorless learning is a teaching strategy designed to prevent a learner from making mistakes during the acquisition of new skills The core principle is proactive intervention to guide the learner to the correct response thereby preventing errors from occurring and becoming part of a behavioral chain In the context of a BCBA teaching handwashing providing full physical handoverhand guidance throughout the entire sequence Option C is a direct application of errorless learning This method ensures that the learners responses are always correct because the prompt is so intrusive that it essentially does the behavior for the learner allowing for immediate reinforcement of a correct response Lets evaluate the other options Option A Backward chaining with errors in earlier steps While backward chaining is a valid procedure if reinforcement is only at the end and errors are allowed in earlier steps it does not fit the definition of errorless learning Errorless learning would require preventing those errors in the initial steps Option B Waiting for an attempt then prompting This scenario describes a leasttomost prompting strategy or an errorcorrection procedure where errors are allowed to occur before a prompt is introduced This is not errorless learning as errors are permitted Option D Waiting for initiation then verbal prompt Similar to Option B this approach allows for a period where the learner might make an error or no response before a prompt is given Errorless learning aims to prevent even these momentary opportunities for error