The reason she left her husband was due to his infidelity. What is a suitable rewording of this statement?

In this context, the chosen answer effectively conveys the essence of the original statement by focusing on the underlying rationale for her decision to leave her husband. The phrase captures the notion that there is a specific reason that prompted her actions, maintaining the emphasis on the rationale of infidelity.

This rewording succinctly communicates the idea that her departure was directly linked to her husband's unfaithfulness. The use of "the reason why she left" mirrors the original structure, making it clear that it is addressing the cause of her departure while retaining the context of infidelity.

On the other hand, the other options, while they may hint at similar ideas, could introduce nuances that shift the focus slightly. For instance, phrases like "the justification for her departure" or "the motive behind her leaving" might imply a more active reasoning process or a defense of her choice, which typically differs from a straightforward identification of reason. "The cause of her leaving," while close in meaning, slightly alters the emotional weight and straightforwardness that “the reason” conveys in the context of personal relationships.