Answer
Scale factor = 2
Explanation
Dilation centered at the origin by a factor of k transforms the point (x, y) into (kx, ky).
Using a scale factor of 2 and applying this transformation to the vertex of triangle ABC, we get:
A(-3, 4) → (2 x -3, 2 x 4) → A'(-6, 8)
B(-3, 1) → (2 x -3, 2 x 1) → B'(-6, 2)
C(2, 0) → (2 x 2, 2 x 0) → C'(4, 0)