What was the catholic church's response to the reformation

The Catholic Church´s response to reformation was the counter reformation, ( also known as Catholic Reformation or sometimes as Catholic Revival),not only as opposed to the potestant reformation but also as an internal revitalization of the Catholic Church itself. Pope Paul III convened the Council of Trent in 1545 to repond to the current issues.

i don't think it's c or d. i think it's either a or b.

hope this .