Answer:
A. 12 square units.
Explanation:
We have been given graph of a triangle and we are asked to find the area of our given triangle.
Since we know that area of a triangle is half the product of height of triangle and base of the triangle.

We can see that MN is base of our triangle and LM is height of triangle, so let us find lengths of MN and LM using distance formula.
Now let us substitute our side lengths is area formula.



Therefore, area of triangle LMN is 12 square units and option A is the correct choice.