Final answer:
The appropriate consulting engagement agreement for providing ongoing internal control training to managerial personnel by the internal audit is a Formal consulting engagement agreement.
Step-by-step explanation:
The question asks which type of consulting engagement agreement is most suitable when senior management requests the internal audit activity to provide ongoing internal control training for all managerial personnel. The correct answer is D. Formal consulting engagement agreement. This type of agreement is appropriate because it provides a structured approach with defined scope, objectives, and duration for the training, which reflects the ongoing and systematic nature of the internal control training requested by the senior management.