If a straight line through the origin bisects the line passing through the given points $\left(\mathrm{acos\alpha },\mathrm{asin\alpha }\right)$ and $\left(\mathrm{acos\beta },\mathrm{asin\beta }\right),$ then the lines 

• A

  are perpendicular 

• B

  are parallel

• C

  have a angle between them of $\mathrm{\pi }/4$

• D

  none of these