In What Sense, According to Quinn and Meeker, Does Religious

In what sense, according to Quinn and Meeker, does religious diversity present a "challenge" for religious people?

A) The fact that similar kinds of arguments could be given for many different religions creates a puzzle about how any one religious view can be rationally justified.
B) Since people of different religions have different ideas about how we should live, living together in religiously diverse societies is a challenge.
C) It is difficult to retain one's religious faith in the fact of so many different religions, each claiming to have support from argument and experience.
D) Religious diversity lays down a challenge to religious people to either prove that their religion is the correct one or become atheists.