Convert the sentence provided below from its passive voice structure to an active voice structure: A decision has been taken to have the proposal reviewed by an external panel.

Correct — C. The passive verb is has been taken, the present perfect, and no one is named as the one who decided.

So the active needs a general subject, they, and keeps the tense: a decision has been taken → they have decided.

The causative have the proposal reviewed is not part of the voice change. It survives in the active sentence as get the proposal reviewed, with the same meaning.

They have decided to get the proposal reviewed by an external panel → option (c).

Why the others are wrong

• (a)
  An external panel has reviewed the proposal. — Has reviewed reports the review as already done. The given sentence reports only a decision to have it done, and this option drops that decision entirely.
• (b)
  The proposal is being reviewed by an external panel. — Is being reviewed is still passive, and in the present continuous. It also drops the decision and reports the review as already under way.
• (d)
  The proposal was reviewed by the panel as per the decision. — Was reviewed is still passive and in the simple past, reporting a finished review. It also turns an external panel into just 'the panel'.

Passive to active: the agent becomes the subject and the tense is kept. Has been taken is present perfect, so the active verb is have/has + past participle.

When the passive names no agent, the active supplies a general one: they, people or someone.

A decision has been taken is the passive of they have taken a decision, and they have decided says the same with a single verb.

'To have the proposal reviewed' is a causative: have or get + object + past participle, for arranging for someone else to do a job.

Key facts

• Present perfect passive: has/have been + past participle, as in a decision has been taken.
• Present perfect active: has/have + past participle, as in they have decided.
• Causative: have/get + object + past participle, as in get the proposal reviewed.
• A passive with no named agent takes a general subject such as they or someone in the active.

Common traps

• Picking (a) because it is active and present perfect, without noticing that it reports the review as done and drops the decision.
• Reading 'by an external panel' as the agent of has been taken, when the panel is the reviewer and no one is named as deciding.

No directly related past PYQ was found.