According to the author, unicorns and salamanders
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. never really existed.
It is mentioned in the passage that "Ancient and medieval writers knew all about unicorns and salamanders; not one of them thought it necessary to avoid dogmatic statements about them because he had never seen one of them."
It means that they never really existed.
Hence, the chosen option will be correct.