The Book and Lecture Suggest That

The book and lecture suggest that

A) we should try to find a definition of religion because then we can decide who is right and who is wrong.
B) we should not try to find a definition of religion because everyone is different.
C) we should try to define religion in a way that is justifiable and helpful, in order to have a reasoned discussion of what we are studying.
D) we can try to define religion if we find it entertaining, but it does not really matter.