If a triangle `A B C ,A-=(1,10),` circumcenter `-=(-1/3,2/3),` and orthocentre `-=((11)/4,4/3)` , then the coordinates of the midpoint of the side opposite to `A` are `(1,-(11)/3)` (b) `(1,5)` `(1,-3)` (d) `(1,6)`