The equations to the straight line through `(a, b, c)` parallel to the `z`-axis are

Options

A. `(x-a)/1=(y-b)/0=(z-c)/0`
B. `(x-a)/0=(y-b)/0=(z-c)/1`
C. `(x-a)/0=(y-b)/1=(z-c)/0`
D. `(x-a)/0=(y-b)/1=(z-c)/1`

Answer

B

Explanation

We know that dr's of z-axis are (0,0,1)
So, dr's of the required line are 0,0,and 1
Now, equation of the line passing through (a, b, c) and having dr's 0,0 and 1 is
`(x-a)/0=(y-b)/0=(z-c)/1`