If $\alpha, \beta$ and $\gamma$ are the roots of the equation $x^3-13 x^2+k x+189=0$ such that $\beta-\gamma=2$, then $\beta+\gamma: \mathrm{k}+\alpha=$

• Correct answer
  A

  $4: 3$
• B

  $2: 1$
• C

  $6: 5$
• D

  $3: 4$

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