Final answer:
The correct answer is option D, which is the only choice that directly applies the Midsegment Theorem of triangles by describing a triangle ABC with midpoints on its sides.
Step-by-step explanation:
The correct answer is option D: ABC with midpoints M and N. This statement relates to the given property that in a triangle, a segment joining the midpoints of two sides is one-half the length of the third side. This property is a consequence of the Midsegment Theorem, which states that the segment connecting the midpoints of two sides of a triangle is parallel to the third side and is half as long. This directly matches the description given in the statement and corresponds to geometry and triangles.
When a line segment joins the midpoints of two sides of a triangle, the resulting line segment is called a midsegment. Therefore, a triangle ABC with midpoints M and N on two of its sides will have a midsegment that is half the length of the third side, which is a direct application of the Midsegment Theorem in geometry.