Final answer:
Delegated authorization is the term for the authority given to a dental professional by a dentist, including an orthodontist, to carry out controlled acts.
Step-by-step explanation:
The authority for a dental hygienist or other dental professional to proceed with a controlled act that has been delegated by a dentist, including an orthodontist, is known as A) Delegated authorization. This term refers to a scenario where a dentist or orthodontist has provided the legal and professional empowerment to perform certain procedures that are otherwise restricted to licensed practitioners. It's essential in ensuring that patient care is delivered safely and effectively within the scope of practice and regulations.