D 
In the diagram below, a circle centered at $O$ has radius $4 \text{cm}$. It is divided into $4$ regions by two chords that are perpendicular to each other at point $N$. It is known that $OM=1 \text{cm}$, $MN=2\text{cm}$. Find the value of: Area of $(I + III) -$ Area of $(II+IV)$ 
(A) $$0$$ 
(B) $$2$$ 
(C) $$4$$ 
(D) $$6$$ 
(E) $$8$$ 