The correct option is A x + 2y - 1 = 0
the center of the given circle is (1,0).
Any line parallel to x + 2y = 3 is given by x + 2y + k = 0
And we know that normal passes through the center of the circle
⟹ 1 + 2(0) + k = 0
⟹k = -1
Hence, the equation of the normal will be : x + 2y - 1 = 0