What is the passive transformation of the fear regarding the lost crew members?

The correct transformation, "are feared to have been lost," effectively conveys the original sentiment regarding the fear about the crew members using a passive structure. In this formulation, the term "feared" clearly indicates that there is an emotional response—specifically, fear—toward the situation of the crew members, without directly assigning the fear to any individual or source. This aligns with the passive construction, which shifts the focus away from the subject performing an action to the situation being acted upon.

In contrast, the other options do not maintain this specific expression of fear. While they suggest different states—such as being "supposed" to be lost or "suspected" to be missing—they lack the direct emotional context of fear. The phrase "are believed to have perished" introduces an element of belief, which may not imply fear and encompasses a certainty about their fate rather than the apprehension associated with worry. Hence, these variations do not accurately reflect the original context of fear regarding the lost crew members in a passive form.