AMC 10A 2010 Problem 6

For positive numbers x and y the operation \spadesuit(x, y) is defined as

\spadesuit(x, y)=x-\dfrac{1}{y} \text {. }

What is \spadesuit(2, \spadesuit(2,2)) ?

Answer Choices
A. \dfrac{2}{3}
B. 1
C. \dfrac{4}{3}
D. \dfrac{5}{3}
E. 2