Find parametric equations for the normal line to the surface $z = 9x^2 + 6y^2$ at the point (2, 1, 42).
$x = 2t + 18$, $y = t + 6$, $z = -t + 42$
$x = 18t + 2$, $y = 6t + 1$, $z = -t + 24$
$x = 2t + 36$, $y = t + 18$, $z = 42t - 1$
$x = 36t + 2$, $y = 12t + 1$, $z = -t + 42$