Many species of animal have become extinct during the last hundred years.

Answer: Option D

Feeble : lacking physical strength, especially as a result of age or illness.
Aggressive : ready or likely to attack or confront; characterized by or resulting from aggression.
Scattered : occurring or found at intervals or various locations rather than all together.
Non-existent : not existing or not real or present.
Extinct : no longer in existence.

Synonym of Extinct is Non-existent