Answer: The correct option is (B) 3.
Step-by-step explanation: We are given to find the length of the leg s in the triangle shown in the figure.
From the figure, we note that
the given triangle is a right-angled one, where
length of the hypotenuse, h = √18 units,
length of one leg, p = 3 units
and
length of the other leg, s = ?.
From Pythagoras theorem, we have

Thus, the length of the leg s is 3 units.
Option (B) is CORRECT.