The correct option is B 1.5 unit
In the given triangle, SR passes though one of the vertex and through the centroid and meets at the opposite side of the triangle.
We know that the median is a line from a vertex of a triangle to the midpoint of its opposite side.
Also, the centroid of a triangle is the point where the three medians coincide.
Hence, SR must be a median of the triangle.
∴ S is the midpoint of the the side PQ.
⇒ PQ = SQ
⇒2x=4x−3
⇒3=4x−2x
⇒3=2x
⇒x=1.5