Fill in the blank using correct alternative.

Seg AB is parallel to Y-axis and coordinates of point A are (1,3) then co-ordinates of point B can be.......

Slope of y-axis will be not defined because the denominator will be 0.

Since AB is parallel to y-axis, so the slope will be same.

Let the coordinate of point B be (x, y).

Slope of $AB =\dfrac{y-3}{x-1}$ . Slope of y-axis is not defined as the denominator of $\dfrac{y-3}{x-1}$ will also be 0.

so,

$x-1=0$

$\Rightarrow x=1$

With x=1 here is only 1 option that (D).

Hence, the correct answer is (1,-3) .