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 $(II+IV)$ 
选项为:A:$$0$$  B:$$2$$  C:$$4$$  D:$$6$$  E:$$8$$  请回答其中一个选项.