Given:
Original figure and enlarged figure
To find:
Which ratios can be used to find the scale factor.
Solution:
Scale factor is the ratio of comparing the corresponding sides of two figures.
Option A:

Length of enlarged side = 6.5
Length of original side = 3.25
It is correct.
Option B:

3.25 is the length of original figure. But here it is mentioned in enlarged.
So, it is not correct.
Option C:

Width of enlarged side = 3
Width of original side = 1.5
It is correct.
Option D:

1.5 is the width of original figure. But here it is mentioned in enlarged.
So, it is not correct.
Option E:

1.5 is the width of original figure. But here it is mentioned in enlarged.
So, it is not correct.
Therefore the ratios can be used to find the scale factor are: