Two similar polygons are shown below:

a coordinate grid is shown from positive 6 to negative 6 on the x-axis and from positive 6 to negative 6 on the y-axis. a polygon p prime q prime r prime s prime is shown with vertex p prime on ordered pair 2, negative 4, vertex q prime on ordered pair 6, negative 4, vertex r prime on ordered pair 4, negative 2 and vertex s prime on ordered pair 2, negative 2. a polygon pqrs is shown with vertex p on ordered pair 1, negative 2, vertex q on ordered pair 3, negative 2, vertex r on ordered pair 2, negative 1 and vertex s on ordered pair 1, negative 1.

which transformation was performed on pqrs to form p'q'r's'?

a dilation factor of 2
a dilation factor of 4
a dilation factor of 1 over 2
a dilation factor of 1 over 4