Answer:
Correct answer is D. the Catholic Church began to lose influence in European countries.
Step-by-step explanation:
A is not correct as in Catholic schools (usually monasteries) Latin was official language. When public schools were opened this changed.
B is not correct as during this period (11th Century) Catholic Church was at its peak, and Latin was dominant language in the church.
C is not correct as Italian was never introduced as official language.
D is correct as this happened after Reformation and many other movements that changed the influence of the church.