When was President Decree No. 1570 signed?

The correct answer is that President Decree No. 1570 was signed on June 11, 1978. This decree is significant as it pertains to specific laws or regulations instituted during the Marcos administration in the Philippines. Understanding the context of the time can provide insights into the political and economic climate of the period, especially regarding governance and development policies.

The other dates listed do not correspond to the signing of this decree, which is essential for historical reference and understanding of legislative timelines in the Philippines. Knowledge about these decrees can be crucial for those studying engineering economics or laws, as they often intersect with industry regulations and standards impacting engineering practices.