Concept:In passive voice with infinitives, the subject receives the action. In active voice, the doer of the action becomes the subject.
Rule / Clue:The original sentence uses “is supposed to have been drafted” – a passive reporting structure with a perfect passive infinitive. The agent is “by external advisors”. To convert to active, make the agent the subject, change “to have been drafted” to “to have drafted”, and adjust the reporting verb to agree with the new subject.
Explanation:First, identify the agent: “external advisors”. Make it the subject of the active sentence. The reporting verb “is supposed” must now agree with the plural subject, so it becomes “are supposed”. Change the perfect passive infinitive “to have been drafted” into the perfect active infinitive “to have drafted”. The original subject “the policy” becomes the object of the active infinitive. Keep the phrase “in complete secrecy” at the end to preserve the full meaning. Option C matches this exactly. Options A, B, and D all change tense, meaning, or omit the correct agent, making them incorrect.
Answer:Option C: External advisors are supposed to have drafted the policy in complete secrecy.