One Reason the French Kings Never Adopted Protestantism Was That

One reason the French kings never adopted Protestantism was that:

A) they were satisfied by the reforms enacted by the 1511 Council of Pisa.
B) the pope promised Francis I that he would summon a new council to reform the church.
C) they already controlled the French church by virtue of having established the right to appoint bishops.
D) there were never more than a handful of Protestants in France.