Convert the sentence provided below from its passive voice structure to an active voice structure: It was being suggested by multiple sources that the operation had been compromised internally.

Correct — A. The stem opens with a placeholder It: "It was being suggested by multiple sources that ...". It stands for the that-clause, and the doer sits after by.

In the active, the agent moves to the front: Multiple sources becomes the subject, suggested the verb, and the that-clause its object.

That clause names no doer, so it stays passive: the operation was compromised internally. Option (a) is built this way. It keeps the doer, the receiver and internally, though both verbs move to the simple past.

Why the others are wrong

• (b)
  The operation was compromised, multiple sources suggested. — Drops internally, which is the substance of the suggestion: that the breach came from inside. A voice change may rearrange a sentence, never cut its content.
• (c)
  The sources were suggesting an operation compromise. — An operation compromise turns the clause into a vague noun phrase and loses internally. The sources and an operation also replace the stem's multiple sources and the operation.
• (d)
  The operation had compromised multiple internal sources. — Reverses the roles. The operation becomes the doer that compromised the sources, while in the stem the sources do the suggesting and the operation is what was compromised.

Passive-to-active conversion has three moves: the agent after by becomes the subject, the passive subject becomes the object, and the verb takes its active form.

A sentence that opens It was ... that keeps its real content in the that-clause. It is only a placeholder, so the active sentence starts with the agent — multiple sources — and the that-clause becomes the object of suggest.

A clause with no by-phrase, like the operation had been compromised internally, has no doer to move and stays passive.

Key facts

• The opening It in It was being suggested that ... stands in for the that-clause.
• In the active, the agent after by becomes the subject: by multiple sources becomes Multiple sources.
• Past continuous passive was/were being + past participle becomes was/were + -ing form in the active.
• A clause with no by-phrase has no doer to move and stays passive.

Common traps

• Making the operation the doer, which reverses who did what
• Accepting a shorter option that drops a detail such as internally
• Holding out for an exact tense match when no option offers one, instead of choosing the option that keeps the meaning whole

No directly related past PYQ was found.