Let \( y=y(x) \) be a differentiable function in the interval \( (0,\infty) \) such that \( y(1)=2 \), and \( \lim_{t\to x} \left(\dfrac{t^{2}y(x)-x^{2}y(t)}{x-t}\right)=3 \) for each \( x>0 \). Then \( 2y(2) \) is equal to:
\( 23 \)
\( 12 \)
\( 27 \)
\( 18 \)