Direction vector n of straight line l?

Is that n? ={m，n，p}={-28， 14，-7 }； ? Normal vector n of plane π? ={4,-2, 1};

Because-28/4 =14/(-2) = (-7)/1=-7; The ∴ normal vector of the straight line l∑ plane π; ∴L⊥ plane π; Therefore, we should choose C;