Final answer:
The authorized controlled act for a nurse when ordered, according to the Nursing Act, is managing labour, which includes care during childbirth and appropriate interventions.
Step-by-step explanation:
The question asks which controlled act a nurse is authorized to perform when ordered, as found in the nursing act. The options provided are: a. putting an instrument beyond the external ear canal, b. managing labour, c. conducting an allergy challenge test, d. supervising the dispensing of a drug in a pharmacy. According to the Nursing Act and the scope of practice for nurses, the correct answer is b. managing labour.
Nurses are trained and legally authorized to manage labour, which includes caring for the patient during childbirth and providing appropriate interventions as needed. The other options listed are not typical responsibilities given to nurses within their authorized scope of practice, especially not without additional certification or context specific rules.