The correct option is "I and III only" because an ordinance, promulgated by the President under Article 123 of the Indian Constitution, has the power to amend any Central Act (Statement I). However, it cannot abridge Fundamental Rights, as no law, including ordinances, can violate the basic structure of the Constitution (Statement II is incorrect). Additionally, an ordinance can indeed have a retrospective effect, meaning it can come into force from a back date (Statement III), aligning with legislative practices to ensure the law addresses situations prior to its enactment. This understanding is crucial for comprehending the temporary legislative powers in the context of an executive's role in Indian governance.