A circle $C_1$ passes through the origin $O$ and has diameter $4$ on the positive $x$-axis. The line $y=2x$ gives a chord $OA$ of a circle $C_1$. Let $C_2$ be the circle with $OA$ as a diameter. If the tangent to $C_2$ at the point $A$ meets the $x$-axis at $P$ and $y$-axis at $Q$, then $QA: AP$ is equal to

• Correct answer
  A

  $1:4$
• B

  $1:5$
• C

  $2:5$
• D

  $1:3$

Hence, the correct answer is option: 'A'.