A new termination option would likely require a remeasurement of the net investment in a lease according to the principles outlined in the accounting standards. If there is a change in the assessment of a termination option, it could lead to a revision of the expected lease term, which in turn may impact the lease liability and related asset recognized on the balance sheet. Similarly, if there's a change in the assessment of a purchase option, this could also necessitate a reassessment of the lease terms. On the other hand, a new payment method option might affect the cash flows related to the lease, but not necessarily the overall lease term or the nature of the lease, so it might not trigger a remeasurement of the net investment in the lease. An existing lease extension option, if already considered in the initial lease assessment, would not require a remeasurement unless there's a change in the evaluation of that option.

Therefore, the options that could lead to a remeasurement of the net investment in a lease are: A. A new termination option D. An existing purchase option

However, it's important to note that the specific circumstances and the terms of the lease agreement would ultimately determine whether a change in any of these options would indeed require a remeasurement.