Let \( \alpha , \alpha+2 , \alpha \in \mathbb{Z} \), be the roots of the quadratic equation \( x(x+2) + (x+1)(x+3) + (x+2)(x+4) + \ldots + (x+n-1)(x+n+1) = 4n \) for some \( n \in \mathbb{N} \). Then \( n+\alpha \) is equal to:
\( 0 \)
\( 1 \)
\( 2 \)
\( 3 \)