The given points are (2, -3) and (2, 9)
The x-component of the two points is the same. Which means the line passing through the given two points is a vertical line and slope of a vertical line is undefined.
You can also validate it using the formula of finding slope.
Slope = (-3-9)/(2-2) = -12/0 = undefined
So, first option is the correct answer.
