What is the appropriate transformation using "when" to imply the timing of an action?

The choice "I left when the bell rang" effectively utilizes "when" to establish a direct relationship between the timing of both actions: leaving and the bell ringing. This construction clearly indicates that the action of leaving occurred at the precise moment the bell rang, which is the intended implication of timing in this context.

This transformation is straightforward and presents a clear cause-and-effect situation linked by the word "when," which establishes that one action happens at the same time as another. In contrast, other options utilize different conjunctions or phrasing that may imply a sequence but do not convey the specific simultaneous timing that "when" provides. For instance, using "as soon as" or "after" conveys a sequence but lacks the direct timing relationship that "when" emphasizes.