AMC 12 2004a Problem 6

Let $U=2\cdot 2004^{2005}$, $V=2004^{2005}$, $W=2003\cdot 2004^{2004}$, $X=2\cdot 2004^{2004}$, $Y=2004^{2004}$ and $Z=2004^{2003}$. Which of the following is the largest?

$\text{(A) } U-V \text{(B) } V-W \text{(C) } W-X \text{(D) } X-Y \text{(E) } Y-Z$