How can the statement about the rock star's wife be transformed to passive voice?

The correct transformation to passive voice emphasizes the action and the entity receiving the action rather than the subject performing it. In this context, the phrase "is said to have had" effectively conveys that someone is reporting or stating something about the rock star's wife, focusing on the idea that there is an assertion about her, without clearly identifying who is making that assertion.

This phrase captures the essence of passive voice, where the attention is drawn away from the doer (the one rumored or said to do the action) and focuses on the action itself and its subject. The choice correctly transforms a possible active construction into passive by using the structure "is said," which is typically used in English to report on hearsay or general belief.

The other options, while similar in structure, use verbs that imply different kinds of beliefs or rumors pertaining to the rock star's wife, but none of these choices aligns as well with the established form of passive voice. Each alternative introduces a different nuance—"rumored," "believed," and "known"—but doesn't maintain the same level of reporting or assertion about what is being said or believed regarding the wife. Thus, the emphasis shifts from a clear passive construction to other subtly active forms in these responses.