B or C?

cnritter

2. Puritan fanatics brought to civil and military affairs a coolness of judgment and mutability of purpose that some writers have though inconsistent with their religious zeal, but which was in fact a natural outgrowth of it.
A)        but which was in fact a natural outgrowth of it
B)        but which were in fact a natural outgrowth of it
C)        but which were in fact natural outgrowths of it
D)        but it was in fact a natural outgrowth of them
E)        which was in fact a natural outgrowth of it

cnritter

答案应为B。which指a coolness of judgment and mutability of purpose ，表明一种属性时应用单数 a natural****，同时与it对应（指zeal）