If $\mathrm{a}, \mathrm{b}, \mathrm{c}, \mathrm{d}$ are four distinct numbers chosen from the set $\{1,2,3 \ldots, 9\}$, then the minimum value of $\frac{\mathrm{a}}{\mathrm{b}}+\frac{\mathrm{c}}{\mathrm{d}}$ is

• A

  $\frac{3}{8}$
• B

  $\frac{1}{3}$
• C

  $\frac{13}{36}$
• Correct answer
  D

  $\frac{25}{72}$

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