Which of the following is a ground for variation of spousal support under the Family Law Act?

The correct answer highlights that a ground for variation of spousal support under the Family Law Act is based on new evidence that was previously unavailable. This is significant because the legal landscape in family law recognizes that circumstances can shift over time, and new information can fundamentally affect the financial circumstances of the parties or the fairness of the original support arrangement. When such new evidence is presented, it provides a valid basis for a court to reconsider the spousal support order, potentially leading to a modification that reflects the current realities of the parties involved.

In contrast, while changes in children's living arrangements, disputes about property division, and changes in tax laws can influence financial situations, they do not automatically serve as grounds for varying spousal support. Changes in children's living arrangements affect custody and child support considerations, while property division disputes relate to asset distribution rather than support obligations. Changes in tax laws may impact individual finances but do not directly provide a basis for varying spousal support unless they relate to new evidence affecting the parties' income or obligations. Therefore, the introduction of new, previously unavailable evidence is the most pertinent ground for a variation in spousal support under the Family Law Act.