Which writer, philosopher, and Christian humanist used his writing to criticize church officials who had become too worldly?

a. Petrarch

b. Erasmus

c. Giotto

d. Machiavelli

It was "a. Petrarch" who used his writing to criticize church officials who had become too worldly. In fact Petrarch was one of the very first humanists to question the Church in this way.