Answer:
2). B
Explanation:
We have been given a triangle ABC, whose midpoints are M, N and O. We are asked to complete the given transformation.
The midpoint theorem states that segment connecting the midpoints of two sides of a triangle is parallel to third side and half the measure of third side. By midpoint theorem:



We can see that by joining midpoints, we get 4 congruent triangles:

We can also see that midpoint M corresponds to vertex C, so midpoint O will correspond to vertex B.
Therefore our required transformation would be
and 2nd option is the correct choice.