Let $a$ and $b$ be relatively prime positive integers with $a\textgreater b\textgreater0$ and $\frac{a^{3}-b^{3}}{(a-b)^{3}}=\frac{73}{3}$. What is $a-b$? 
选项为:A:$$1$$  B:$$2$$  C:$$3$$  D:$$4$$  E:$$5$$  请回答其中一个选项.