AMC 10B 2005 Problem 4

For real numbers a and b, define a \diamond b=\sqrt{a^{2}+b^{2}}. What is the value of

(5 \diamond 12) \diamond((-12) \diamond(-5)) ?

Answer Choices
A. 0
B. \dfrac{17}{2}
C. 13
D. 13 \sqrt{2}
E. 26