Answer:
The correct option is B.
Step-by-step explanation:
Given information: In ∆ GHK point M is the midpoint of GH.
If a line perpendicular from a vertex to the opposite side of the triangle, then it is called altitude of a triangle.
If a line segment joint a vertex of the triangle to the midpoint of the opposite side, then it is called median.
If a line segment bisect one of the vertex angles of a triangle, then it is called angled bisector.
If a line from a vertex perpendicular to the opposite side and passing through its midpoint, then it is called perpendicular bisector.
Since side GH is opposite to the vertex K and M is the midpoint of GH, therefore the line segment KM is median of the ∆GHK.
Therefore the correct option is B.