Answer:
1st option is correct i.e., 1 over 2
Step-by-step explanation:
Given that Triangle ABC transformed to Triangle A'B'C'.
Coordinated of Triangle ABC are A(2,6) , B(2,4) and C(4,4)
Coordinated of Triangle A'B'C' are A'(1,3), B'(1,2) and C'(2,2)
Scale factor of Dilation is the no. of times coordinates of vertices of a figure increase or decrease.i.e.,
if A(a,b) ⇒ A'(c,d)
where, a.k=c & b.k=d then k is scale factor of dilation.
Value of k is same for all vertices.
For coordinates of A & A' ,we have 
For coordinates of B & B' ,we have 
For coordinates of C & C' ,we have 
Therefore, the scale factor of dilation is
since in all cases 
1st option is correct i.e., 1 over 2