Final answer:
The opening of the Suez Canal was significant for the Illustrados' nationalist movement as it reduced travel time for the educated reformists between Spain and the Philippines, enabling better communication and quicker exchange of ideas.
Step-by-step explanation:
The significance of the opening of the Suez Canal to the nationalist activities of the Illustrados in the Philippines was substantial. It greatly reduced the travel time from Spain back to the Philippines. This was crucial as many of the Illustrados were educated in Spain and then returned to Philippines to advocate for reforms and nationalist sentiments. The opening of the Suez Canal allowed for quicker and more efficient communication and exchange of ideas between the reformists in the Philippines and their supporters in Europe. Hence, it accelerated the spread of nationalist ideas and enabled the Illustrados to be more effectively involved in the intellectual and political discourse of the era, contributing to the rise of nationalism in the Philippines