The correct option is A x+3y−10=0
Mid point of line segment joining (2,1) and (3,4) ≡(52,52)
Slope of the line joining (2,1) and (3,4)
m=4−13−2=3
The required line is perpendicular to it, hence slope of the line =−1m=−13
Equation of perpendicular bisector : y−52=−13(x−52)
⇒2y−5=−13(2x−5)⇒x+3y−10=0