6308. All the characters in this novel are fictitious.

✅ The correct answer is option D.
unbelievable : not able to be believed; unlikely to be true.

unreliable : not able to be relied upon.

infamous : well known for some bad quality or deed.

unreal : imaginary or illusory.

fictitious : not real or true; imaginary or fabricated.

Synonym of fictitious is unreal