If the equation of line is $x=ay+b$; $z=cy+d$. Then its symmetric form is

• A

  $\frac{x-a}{b}=\frac{y}{1}=\frac{z-c}{d}$

• B

  $\frac{x-b}{a}=\frac{y}{1}=\frac{z-d}{c}$

• C

  $\frac{x+a}{b}=\frac{y}{1}=\frac{z+c}{d}$

• D

  $\frac{x+b}{a}=\frac{y}{1}=\frac{z+d}{c}$