Question

What is the scale factor of the dilation of line segment BA?

Answer 1

we know that

If

the two triangles, ABC and A'B'C are similar

then

$CB/CB' = CA/CA' = BA/B'A'$

$CA/CA'= \frac{4}{20}$

$CA/CA'= \frac{1}{5}$

$BA/B'A'= \frac{1}{5}$

$B'A' = 5BA$

therefore

the answer is the /option D)

$5$

Answer 2

The two triangles,  ABC, A'B'C are similar

so

CB/CB' = CA/CA' = BA/B'A'

BA/B'A' = 4/20

BA = 1/5 B'A'

BA = D.F B'A'  (DF is dilation factor)

DF = 1/5