In the figure given below, $\text{AB}$ is the chord of a circle with centre $\text{O. AB}$ is extended to $\text{C}$ such that $\text{BC = OB}.$ The straight line $\text{CO}$ is produced to meet the circle at $\text{D}.$ If $\measuredangle \text{ACD} = y^{\circ} \text{ and } \measuredangle \text{AOD} = x^{\circ}$ such that $x=ky,$ then the value of $k$ is
- $3$
- $2$
- $1$
- None of these