98.
The answer is: D
Explanation
Option D: The notification is ultra vires, as the enactment does not clearly and specifically provide for retrospective levy of taxes.
Explanation:
According to the principle, for delegated legislation to have retrospective effect, the power to do so must be explicitly and clearly conferred by the parent enactment. In this case, while the statute permits the authority to give retrospective effect to its regulatory notifications, it does not specifically provide for the retrospective levy of taxes. Therefore, the notification levying a developmental tax on leather industries retrospectively is ultra vires, meaning it is beyond the powers of the authority as granted by the statute.