Answer:
Three-fifths

Step-by-step explanation:
This question is mathematics not history; however, the solution is as follows.
Given
Line Segments A'B' and AB
Center of Dilation = P


Required
Scale factor of dilation;
The scale factor of dilation is defined as thus;
Scale Factor is the ration of the distance between the center points and origin of the dilated line segment to the original line segment;
In other words;

Substitute
and


Hence, the scale factor of this dilation is Three-fifths or
