Answer
Find out the how long is woman shadow .
To prove
Let us assume that the height = x
Let us assume that the shadow = y
(As shadow increase with the increase in the height.)

x = ky
Where k is constant of proportionality.
As given
A 10 ft tall statue standing next to a woman casts an 18 ft shadow.
10 = k × 18

As given
If the woman is 5 ft tall .
Let us assume that the shadow of woman be s .
Put in the proprtionality equation .
5 = k × s

Compare the value of k .


s = 9 ft
Therefore the shadow of the woman be 9 ft .
Option (C) is correct .