In a regular $15-$sided polygon with all its diagonals drawn, a diagonal is chosen at random. The probability that it is either a shortest diagonal nor a longest diagonal is

• Correct answer
  A

  $\frac{2}{3}$
• B

  $\frac{5}{6}$
• C

  $\frac{8}{9}$
• D

  $\frac{9}{10}$

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