The question did not show the original vertices of A, B, and C.
Generally, for a triangle ABC that is dilated by a scale factor of four to form triangle A'B'C', the coordinates of vertices A', B', C' are:
For A(x, y)
The coordinate of vertex A' will be A' (4x, 4y)
For B(x, y)
The coordinate of vertex B' will be B' (4x, 4y)
For C(x, y)
The coordinate of vertec C' will be C' (4x, 4y)