The range of a discrete random variable X is $\{1,2,3\}$ and the probabilities of its elements are given by $\mathrm{P}(\mathrm{X}=1)=3 \mathrm{k}^3, \mathrm{P}(\mathrm{X}=2)=2 \mathrm{k}^2$ and $\mathrm{P}(\mathrm{X}=3)=7-19 \mathrm{k}$. Then $\mathrm{P}(\mathrm{X}=3)=$

• Correct answer
  A

  $\frac{2}{3}$
• B

  $\frac{2}{9}$
• C

  $\frac{1}{9}$
• D

  $\frac{4}{9}$

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