The correct answer to this open question is the following.
Although there are no options attached and further context, we can comment on the following.
who lead the secularization and what were the effects on priests and followers?
The individual who led secularization was priest Pedro Peláez (1812-1863).
He was an important figure of the clergy in the Philippines and defended the rights of the priests in those difficult years. He was the one who fought for the secularization of the priests in the Philippines and started the Filipino revolution.
Today, Peláez is revered as an important figure of the Catholic religion in the Philippines and is in the process of beatification. His case is in the Vatican.