The slope of a line parallel to y-axis is

1. 0

2. 1

3. -1

4. not defined

The slope of a line which makes an angle of 30° with the positive direction of x-axis is

1. 1

2. $\dfrac{1}{\sqrt{3}}$

3. $\sqrt{3}$

4. $-\dfrac{1}{\sqrt{3}}$

The slope of the line passing through the points (3, -2) and (-7, -2) is

1. 0

2. 1

3. -$\dfrac{1}{10}$

4. not defined

The slope of the line passing through the points (3, -2) and (3, -4) is

1. -2

2. 0

3. 1

4. not defined